My Stepsister is My Ex-Girlfriend - Volume 4 - Chapter 2

The Ex-Girlfriend Does Reconnaissance

“Like a couple that’s been living together for three years.”

I thought I heard RADWIMPS playing from the living room, so I poked my head in, only to find Mizuto watching Your Name. Finding it curious, I approached my little stepbrother. He was leaning against the back of the couch while gazing at the extremely beautifully drawn Tokyo landscape.

“What are you doing?” I asked.

“Watching a movie.”

“That’s rare.”

“Not my choice.”

What does that mean? It was almost as if he was implying that someone else had wanted to watch it.

“Oh, Yume-san. Greetings. Pardon the intrusion.” A feminine voice came out from nowhere, causing me to jump. But then I saw an outstretched hand lazily waving from the couch. Laying there was none other than Higashira-san, using Mizuto’s lap as a pillow.

“Higashira-san... What are you doing?”

“Enjoying a film.”

That is not what I’m asking about. She was resting her head on his lap as if it was the most natural thing in the world. That’s what I wanted to know about.

“Mizuto-kun revealed to me that he hadn’t experienced Your Name. This was a problem that needed prompt correction, so here we are. There shouldn’t be a single person in Japan who hasn’t seen this movie. It is imperative—an absolutely imperative educational experience for every citizen in this country.”

“Japan’s education policy has taken a pretty drastic turn...” Mizuto quipped.

“After this, we will immediately transition to 5 Centimeters Per Second.”

“Not Weathering With You?” Mizuto listlessly asked.

Their conversation was so incredibly casual. Mizuto was acting no different than usual while idly playing with her fluffy hair. They were the spitting image of a couple...or maybe a dog and its master. I wasn’t sure which fit better.

I could feel thorny feelings start filling my head. I’ve had my doubts about their relationship many times before, but right now, it felt like I’d walked in on a date. Was it possible that they were dating and had been lying to us this whole time? Maybe after her confession, they’d ended up getting together, but it was hard to tell us, so they stayed quiet about it... Was that why he hadn’t kissed me the other day?

The scene played back over in my head.

“Y-You— Right now, you were totally—” I had said.

“I did exactly what you said. I showed my feelings through my actions,” he’d replied.

Remembering it only made the thorny, agonizing feelings inside of me well up further. I wanted to clear my mind, so I sat next to Mizuto.

“What’re you doing?” Mizuto asked, shooting me a look.

“I’m watching too.”

I sat just far enough away that I wasn’t anywhere close to touching his lap, shoulder, or even hand. My eyes kept flitting down to Higashira-san.

“I very much enjoy how despite them not conversing with each other directly, they’re slowly becoming a bickering couple,” Higashira-san commented.

This is a good chance. A certain job had been requested of me. While she was nonchalantly giving her otaku commentary, it was up to me to discern the true nature of their relationship.

“So what’s the deal with Higashira-san?” This question had been enthusiastically asked this morning, not by a gossip-loving student, but by Yuni Irido—my mom.

I had been in the midst of checking for new books on my phone.

“Her...deal? What do you mean?” I asked, raising my head.

“Well, she’s been over almost every single day since summer break started. I’m just wondering what’s the deal with her and Mizuto-kun. Aren’t they a little too friendly to be exes?”

Let’s back up even further and review how we got here. Due to a poorly phrased statement by Higashira-san, both mom and Mineaki-ojisan came to be under the impression that she was Mizuto’s ex. They were both very interested in this sudden development for their son and cornered Higashira-san each time she came over. All they ever managed to do was frighten her, though.

“I agree that they’re friendly...unnaturally so...”

“Right? Right?! I’ve talked it over with Mineaki-san, and we think that maybe she was too embarrassed to say that they’re still together, so she lied. Anyway, Yume... Could you do some reconnaissance work for us?”

“Sure... Wait, what?”

I’d reflexively agreed to her request without really listening. Reconnaissance? Huh?

“Higashira-san is too nervous around us, so since she has her guard down around you, we were thinking that you could maybe talk to her and see what’s what.”

“Wh-Why should I do that?”

“You’re curious too, aren’t you?”

“Well...I guess...”

“Great! Give me the juicy deets later!”

She hadn’t left any chance for me to refuse. Why couldn’t her aggressiveness have been passed down to me? I silently cursed my genes.

The two main characters were currently in the midst of a romantic comedy. I hadn’t seen this movie for a while, but if I remembered correctly, I’d seen it right before I’d started dating this guy. Now that I was watching it again, a certain part was really striking a chord with me—the heroine trying to hook the protagonist up with another girl.

I shot a glance at the two next to me. Their expressions were blank as they stared at the screen—not a thought behind their eyes, as far as I could tell. They didn’t look bored. If anything, their lack of expression meant that they were incredibly invested in the story. They really were two peas in a pod.

“Mm... It’s hot...” Higashira-san muttered as she wriggled around on Mizuto’s lap.

When she’d first started coming over, she’d worn the clothes that Akatsuki-san and I had picked out for her. Recently, though, she’d been treating our house like it was her own. Today, she was wearing jeans and a short-sleeved hoodie.

The air conditioning was set at a higher temperature, which may have been uncomfortable for her in that outfit. I reached for the remote to lower the temperature, but before I could... Zrrrp! Higashira-san had partially unzipped her hoodie.

“Phew...” Higashira-san sighed, then turned her attention back to the movie.

Not me. I was too distracted by what was underneath her hoodie. She was wearing a tank top, of all things! She was practically in her underwear! Akatsuki-san had declared that this type of shirt encroached “slut territory.” It stretched tightly across her skin, giving her well-endowed chest a very clear shape and exposing her pronounced cleavage. And one of her bra straps had even fallen off her shoulder!

I stared at her intensely, getting increasingly annoyed, but Mizuto continued to calmly watch the movie as if nothing was happening. I didn’t want to interrupt him, but that was my only option to warn him about Higashira-san’s actions.

Am... Am I the crazy one? Am I missing something? Why didn’t she just take her hoodie off? Did she have some kind of plan that involved only unzipping it down to her boobs? Or did she do that because she simply couldn’t be bothered to put it back on?

While I was toiling in my thoughts, we’d reached the halfway point in the movie. Mizuto’s eyes were now firmly glued to the screen. And then Higashira-san dealt the next blow.

“Mm... Itchy...” Higashira-san mumbled, twisting around before scratching herself.

I initially thought she really was itchy, and that she was innocently moving to make it easier to scratch herself. But I should’ve known better. Isana Higashira is a person who always defies expectations.

Higashira-san slipped her hand down beneath her hoodie and then into her tank top. Huh? Wh-What are you doing?! My question was immediately answered by the quiet sound of something unclasping. No way... I knew that sound. Every girl knew that sound. It was a part of our daily routine. But there was no way...right?

Even Higashira-san wouldn’t do that with Mizuto right there...right? But my hopes and expectations were immediately shot down in the next moment. Higashira-san had stuck her hand towards her chest, under her clothes—no, under her bra.

She’d unhooked her bra, stuck her hand right on in, and started enthusiastically scratching her boobs! I totally got it—I really did. It gets hot under there. I was empathetic. There were more times than not that I wanted to scratch there, but...now?! There’s a guy right there! There are other people here for that matter! So why?! What are you doing?! I hesitate to do that even in front of my mom! I can’t believe my eyes...

“Phew...” Higashira-san sighed once again, and a look of relief spread across her face. Just like that, she moved her hand away and rehooked her bra as if nothing had happened. I know how relieved you are, but I’m definitely going to lecture you on this later. Count on it. 

I decided to tell Akatsuki-san about it too. She’d never dress in clothes that showed her bra—never mind such a messy outfit—in front of a guy. She’d always show up fully dressed. It didn’t matter how comfortable she was around them. She’d never do anything like wear only an oversized T-shirt around someone. I knew she’d be on my side. Higashira-san was the crazy one. Together, we’d give her a strict lecture.

“I’m going to get a drink...” I said.

“Mmhmm.”

“Okay.”

I got up from the couch, lightly holding my hand to my head. The difference in our common sense made my head spin. How could anyone be that unguarded? Also, how unobservant could Mizuto be?!

Their behavior exceeded that of couples. It was like they were living together. They were acting like a couple that had been living together for three or so years. If Mizuto had suddenly stuck his hand down her shirt, she probably would’ve just said a one-off comment about how it tickled or something. It was that kind of atmosphere.

It wouldn’t be weird if the question of marriage came up and they nonchalantly agreed to it. The term “close proximity” didn’t even begin to describe it. How could this happen? How could the two of them have this atmosphere when they didn’t even live together?! We’re not like that and we actually live together!

None of this made sense. But the weirdest part about it was the fact that despite him rejecting her, they were still this close. Their relationship should’ve been strained, not ingrained! It made me feel like a fool that Akatsuki-san and I spent any time genuinely worrying about whether they could go back to being friends.

At this point, it seemed crazy that the two of them could ever not be friends. They were a miracle. How many people in the world were this in sync with each other? I’d made way more friends than he had in high school, but watching the two of them made me feel like I was losing.

I was jealous of them. I really was. But I wasn’t about to do something to mess up their relationship.

I returned to the couch with a pitcher of barley tea and a cup, which I promptly filled up. Just as I started to drink, Mizuto interrupted me.

“Give me some too.”

“Huh?”

“I’m thirsty,” he continued, his eyes still firmly glued to the screen.

“I would’ve brought you some if you’d asked.”

“I forgot.”

Wow, he’s so into this movie. I kinda knew what he was into from when we were dating. Whether it was classic literature, a light novel, a mystery novel, or a movie, he liked works in which the creator’s personality was on full display.

Hm, I see. He wasn’t really in the habit of watching anime movies, but Makoto Shinkai was apparently right up his alley. Higashira-san turned her head on Mizuto’s lap to look up at him. Her lips were curled into a smile. Apparently, this had gone exactly as she’d planned.

His words from when he rejected Higashira-san played back in my head. “My small heart only has room for one more in it. I’m a petty guy. I only have the capacity to truly face one person right now, and that seat is already filled, though she has no right to it.”

I was the only person who knew exactly who filled that seat. But...

“Fine, here. I already drank from it, though.”

“Thanks,” he said, blindly taking the cup before gulping the tea down.

He may have been a string bean, but right now, he looked like a proper guy. After finishing, he handed the cup back to me, and I poured more inside before putting it to my lips.

“Huh?”

The cold tea flowed into me, washing away all the agonizing feelings.

“Um...” Higashira-san gave Mizuto and me a confused look.

“Mmm?”

“Hm?” Does she want tea too?

But I was sucker punched by her next statement. “You two just shared an indirect kiss...”

“Huh...?”

“Uh...?”

Mizuto and I looked at each other and then down to the cup. Our lips hadn’t touched, but they’d both touched the cup. An indirect kiss.

“Oh...” It looked like the dots connected in Mizuto’s head, but he turned back to the screen.

Seeing his nonchalant reaction made Higashira-san look at him with an expression that almost said “That’s it?”

An indirect kiss... That rang a bell. I forgot that was a thing. I resumed drinking my tea.

“Wait... Seriously? That doesn’t bother you? Is this what it means to be a family? Or, perhaps, is this just how high schoolers are?”

It wasn’t like we’d used each other’s toothbrushes or chopsticks. This was nothing. We’d lost that kind of pure innocence long ago. In this regard, he’d yet to share an understanding with her. As soon as I thought that, I felt some of those agonizing feelings disappear.

The credits rolled and Mizuto slumped against the couch. Ultimately, Higashira-san had spent the entire two-hour duration on his lap.

“How was it?” she asked, looking up at him.

“It was good.”

“What did you enjoy specifically?”

“At first, I was really taken in by the beautiful scenery, but I started to get really invested in the gimmick and how that all worked. The smaller details kinda made it seem like the director was putting his fetishes front and center. Overall, it felt like it had the functional beauty of a Hollywood movie. All these pieces gave it an ineffable charm.”

He said that all in one breath?!

“Right, the fetishistic aspect! I completely understand!” Higashira-san jumped up, her eyes sparkling. “Wasn’t it great how he couldn’t stop rubbing his boobs?”

“Oh yeah, that’s a really common trope with body swapping, right? I never expected such a niche genre to be popular in Japan.”

“Every Makoto Shinkai film after Your Name has demonstrated his skill at creating a movie that appears mainstream on the surface but is filled with his fetishes that he forces upon the viewer. It’s similar to... Oh, yes! It’s similar to forcing an innocent girl to watch an uncensored porno.”

“Yellow card.”

“What?! W-Wait, I wasn’t attempting to make a dirty joke. Have you not read Yu Yu Hakusho?! Does your father possess a copy by chance?!”

As knowledgeable as I was about the mystery novel genre, the conversation that the two of them were having was filled with references to different subcultures from all over the place. If I was an otaku like Higashira-san, would we have been able to stay this friendly?

I immediately brushed off that pointless hypothetical. Being on good terms with him wouldn’t fix who he was at his core, nor would it make me any less disillusioned. I didn’t want to be like Higashira-san. If I was, I probably wouldn’t have become friends with Akatsuki-san and the others.

“Phew... Focusing on a movie for two hours is exhausting,” Mizuto said, staring at the ceiling.

“You just don’t have any stamina,” I quipped. He did nothing but read books all day. How was this more draining?

“Oh, then in that case...” Higashira-san suddenly sat up straight and patted her thighs. “It’s your turn now. Rest your head on my lap.”

“Okay, then...”

“Wait, no, no. Stop!” I frantically grabbed Mizuto’s shoulder as he was about to lie down. “You can’t! That’s like... You just can’t!”

“Why not?” he asked.

“For what reason?” Higashira-san tilted her head curiously.

The reason lies with that chest of yours! If he lay down on her lap, he’d be at a perfect angle to...

“I’m offering the lap of a high school girl. It’s very comfortable. Act now, and I will even add an ear cleaning. I don’t do this for just any boy,” Higashira-san said through a suspicious smile. Mizuto’s eyelids drooped a bit.

“Why do you have to make it sound so weird?! Where did you even learn that from?” I exclaimed.

“Higashira’s ear cleaning sounds like a nightmare...” he said.

“Huh?”

“Wha—”

Mizuto leaned not towards Higashira-san but towards me...and then onto my lap. He shifted around a little, trying to find a comfortable spot, before dozing off.

Higashira-san and I both fell silent. Neither of us could believe what had just happened. Ever since summer vacation began, he’d been sleeping until the afternoon. Thanks to that, he often got sleepy around nighttime. Even so, how could he fall asleep so comfortably on someone else’s lap...?

“May I interpret this as Mizuto being so uninterested in me cleaning his ears that he went to you instead?”

“I think that’s what happened...”

“How rude. Do I really look like I’m lacking in dexterity?”

“Honestly? Yes.”

“S-Seriously?!”

For the life of me, I couldn’t imagine Higashira-san knitting.

“But...” Higashira-san said in a low voice while moving in front of me. She crouched down and looked at his sleeping face.

“I got to see how cute he looks while he sleeps, so I’ll forgive him. Heh heh heh.” A bright smile spread across her face as she poked his cheek.

Seeing this, there was only one thing I could think. She really does love him. Even though she had been rejected—even though she knew that she couldn’t be his girlfriend—she couldn’t help how much she loved him. If Mizuto treated her like one would treat their dog, she treated Mizuto like one would treat their cat. Higashira-san was usually so expressionless, but she was nothing but smiles as she watched him sleep.

“This is a good opportunity. Perhaps I should clean his ears regardless.”

“What? Are you serious? Isn’t it scary to stick things in ears?”

“Oh, I understand that sentiment. When my mother first cleaned my ears, I was frightened. I truly wished for her not to begin a treasure hunt in my ear.”

“Uh-huh...”

“Perhaps a peck instead.”

“Yeah, that’d be— Huh?!”

The conversation had flowed so smoothly that I’d ended up nodding, but... What did she just say?! Higashira-san was staring intently at Mizuto’s face.

“Higashira-san... Um, did you just say ‘peck’?”

“Yes. He would be none the wiser.”

“True, but... Huh? That’s what you want your first kiss to be like?”

“Hm... Certainly, a better location and atmosphere would be preferable. And I won’t be able to insert my tongue if he’s not conscious.”

“What kind of first kiss are you trying to do?!”

“In addition, he won’t be able to get caught up in the moment and disrobe me either.”

How much of a horndog are you?!

“I can’t believe you’re able to endure just being close friends with the way you think.”

“I am putting in a decent amount of effort. Honestly, I get inexplicably aroused whenever he pats me on the head. I completely understand heroines whose cheeks flush when they receive a head pat.”

“You do know that they aren’t aroused or anything right? That’s not why their cheeks are red!” She’s been damaged by shojo manga.

“Truthfully, when I confessed to Mizuto-kun, I was partially thinking about his body.”

“Really?!”

“Of course! Being on good terms with someone and being able to engage in sexual relations with them is sublime, wouldn’t you agree?”

“Um... Hm...” She wasn’t wrong.

“Here’s an example: while I enjoy all-ages visual novels, if there is an adult version, I’d prefer to play that. Does that make sense?”

“No. Not at all.”

“Simply being friends with him limits what we could possibly do together,” Higashira-san continued, putting her face close to his. “I would’ve liked to see a horny Mizuto-kun.” Her face was expressionless, making it hard to read, but for some reason, it made my chest feel tight.

Maybe it’s because I was seeing what my past self could’ve been. I knew that my past self and Higashira-san were completely different, but they kept overlapping in my mind. If he had rejected me two years ago at the end of summer vacation, would we have been able to continue being friends? Would we have been able to stay close friends like he and Higashira-san?

“All I’m saying is that there’s a certain type of friend that would allow for friendship and the benefits of a carnal relationship.”

“You know that I won’t support you if you try to go that route.”

“Of course! I wasn’t referring to friends with benefits. You misinterpreted my words.”

“You phrased it like that on purpose!”

I misinterpreted... I misinterpreted her, huh? Misinterpretation is the main reason so many confessions and the resulting relationships don’t work out—the root of all evil, so to speak.

“Hm...” Higashira-san continued to stare at Mizuto’s face while restlessly shaking her hips in a tantalizing way. Suddenly, she shot to her feet.

“May I...borrow your restroom?”

“Huh?” Is she...trying to do what I think she’s trying to do? In someone else’s house?!

“Hm?” Higashira-san tilted her head in confusion at my reaction. But it seemed like she’d realized what I was thinking because her face turned a crimson color. “I-It’s not what you think! I simply need to urinate!”

“O-Oh... Okay...” She’d been talking about all these dirty things, so my mind had jumped straight into the gutter.

“I must say, I’m surprised.” A teasing smile crept across her face. “Mizuto-kun claims that you don’t possess this sort of knowledge, but...it seems you do.”

“W-Well, I am a high schooler. I’ve taken health classes.”

“Heh heh heh. I enjoy those kinds of stories which feature the beautiful, top-of-her-class honor student. It very much gets the juices flowing.”

“You’re sooo gross!” I didn’t bother coming up with a clever retort or anything. I just insulted her, prompting her to scurry away.

I do possess this sort of knowledge. I’m just not comfortable with it. I’d also been putting on an act while around him...because I was scared of any misinterpretations.

With Higashira-san gone, the room fell silent except for the clock, which ticked away as Mizuto slept, softly breathing. I looked down at my thighs, which currently had a slight weight on them. His long eyelashes rested on one another and his bangs slightly covered his eyes. As I used my finger to move them out of the way, their soft, smooth sensation remained.

Soft bursts of air escaped his thin lips. I knew what they felt like. They were gentle but sometimes dry. Sometimes I’d lent him my lip balm before going back in for more...and sometimes (as a joke, of course), I’d put it on him with my own lips.

It had been awkward at first. It took everything I had, but our lips only lightly touched one another’s. We had to tilt our heads to avoid our noses touching, and it nearly became a game in which we had to guess where the other was going. Then we laughed and the romantic atmosphere dissipated.

After a while, it became an unwritten rule that I’d tilt my head right. I’d get embarrassed by how rough my breathing got, though, so we couldn’t kiss for too long.

We’d kiss for three seconds at a time, separate, and catch our breaths. While we did, we’d gaze into each other’s eyes, and then kiss again. Then it’d end when we both tapped each other on the back. These were the rules that we’d made up. Rules that only we knew—rules that he probably still remembered. Even if he and Higashira-san started dating, she’d never know about them.

I leaned forward, and my hair fell to my right. I moved it behind my ear as I did when I read. I’d been able to play it off before, but it was hard to do when he was sleeping. Part of me wanted those feelings to return. The ones that made me feel so light, like I was floating. The ones that made me feel as if my head was going to boil over. The ones that made me crave more and more and fall deeper in love.

When was the last time I’d felt like that? It’d been a little before our relationship got messed up. Probably last June or so. The feelings that’d been sleeping inside me for a year and two months were starting to well up and were about to overflow.

Suddenly, Higashira-san’s words played in my head. “I would’ve liked to see a horny Mizuto-kun.” I would too. I’d wanted to see him like that so, so, so many times. But he hadn’t even given me that special look in so long—the face he’d make when I was the only person reflected in his eyes. Nor had I felt his thin arms that he’d tightly wrap around me, like he was saying that no one else could have me. And the sensation of our bodies seemingly melting together.

As soon as I remembered that, I was overwhelmed by a need to see all of that again. I knew I shouldn’t, but I couldn’t stop myself. This... This is simply lust. Then I felt that desire being chilled further and further by something. It was the memory of him rejecting the kiss.

I had remembered our time together, was filled with my old emotions, and tried to do one of the same old things we used to. There were a lot of times in the four months that we lived together I’d wanted to do that. But...that was just because of our lingering feelings. There was a hole in my heart, and he had the key to fill it—and I yearned for its return.

It was shameful. Pitiful. Pathetic, even. I couldn’t accept that Higashira-san’s once-in-a-lifetime confession had ended in failure because of my desires. It was a misinterpretation. We were misinterpreting things.

I took a deep breath and slowly moved his head off my thighs before standing up. I couldn’t let myself get worked up by these feelings, especially when I’d given Higashira-san grief for essentially the same thing. I needed to cool off. I slowly walked out of the living room to the other bathroom.

I looked at myself in the mirror, and a girl with a completely flat, expressionless face looked back at me.

“So, how’d it go? What’s going on between Mizuto-kun and Higashira-san?”

It was now night, and mom was excitedly asking me for the results of my reconnaissance.

“They’re very good friends,” I answered honestly.

“Definitely! What else?”

“That’s it.”

“What?!” Mom looked very discontent with my answer, but I wasn’t lying. “Don’t you have any specifics? Like...what did they do?”

“Uh... Mizuto-kun let Higashira-san rest on his lap...”

“Oh!”

“Higashira-san said she felt hot and suddenly took off a layer...”

“Wow!”

“She suddenly felt itchy and scratched the inside of her bra...”

“Uh...?” Mom’s face had changed from very interested to very confused. It was only natural.

“Also, remember that this all happened right in front of me as if it was normal.”

“Uh... Huh?!” Mom tilted her head, incredibly confused. “They sound like a couple who’ve been living together for three years.” Wow, there’s that mother-daughter connection. “But they suit each other, don’t you think? Mizuto-kun has an aura of mystery just like hers, so a girl who marches to the beat of her own drum is perfect!”

“If you say so.”

If Higashira-san’d asked me for help before she confessed, I would’ve wholeheartedly supported her. I truly believed that there wasn’t a boy and girl in this world who got along better than they did. Even so, that didn’t mean that they would end up dating. Humans really are complicated.

“In that case, you can’t get careless, Yume.”

“Huh?” My heart stopped at her words. W-Wait, why me? Does she know about—

“Mizuto-kun’s gonna leave you in the dust. You need to find yourself a nice guy too! You’re so cute, I bet you’ll find one in no time!”

“O-Oh... Yeah...” So that’s what she meant. But me? With a guy other than Mizuto? “This isn’t a race. I’ll take my time.”

“Aww...”

It’s unfortunate. It’s very, very unfortunate, but her impression of us is the biggest misinterpretation of them all.