The Case Where I Found Out My Big Sister with a Brother Complex Was Actually My Stepsister, Tried to Hide It, but She Found Out Immediately and Became Uncontrollable - 24-25

Chapter 24:  There’s Something off About My Big Sister

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“Tsunagi, can I talk to you for a bit?”

After the first term closing ceremony ended and I was just about to head home, Hasumi called out to me saying she wanted to talk, so I stayed in the classroom to speak with her.

“What did you want to talk about?”

“There’s going to be a fireworks festival nearby during summer break. Tsunagi, are you interested in that kind of thing?”

“I am. I go see it every year with my big sister, at least.”

“With your big sister… I see.”

Hasumi lowered her head and muttered something.

Oh right… I’d completely forgotten, but it’s already the fireworks season.

Though her face was still lowered, Hasumi soon looked up and spoke.

“If you’re interested in fireworks, how about going with me this year? We always hang out together, and we even went around the cultural festival as a pair, so I was hoping we could make some summer memories together too.”

“Got it. Let’s go together.”

“Eh, really…!?”

“Yeah… Oh, but would it be okay if I invited my big sister too? Since we’ve always gone together every year, it’d feel kind of lonely to suddenly stop doing that this year.”

“Ah… Yeah, that makes sense. Sure, that’s fine.”

Hasumi looked away as she answered.

“Thanks. Okay then, let’s head home.”

With that, the conversation wrapped up, and I started walking out of the classroom to go home—when suddenly, Hasumi pressed her body against my back and grabbed the back of my shirt with both hands.

“Sorry, Tsunagi… But, is it really no good if it’s just the two of us?”

“Huh…?”

If she asked whether it was “no good,” then it wasn’t like I was saying no—but honestly, there was still a part of me that wanted to go with my big sister too.

“I’m fine going with just you, Hasumi, but I think we’d have even more fun if my big sister came along too and the three of us enjoyed the fireworks together.”

“…Yeah, you’re right. Sorry for saying something weird.”

“You don’t have to apologize. If you said you were bringing your big sister along, I’d probably feel like I wanted to go with just you too.”

“That might be a bit of a different situation, but… Thanks for trying to understand how I feel.”

Hasumi let go of my back and moved to stand in front of me, smiling gently as she spoke. She usually kept a calm demeanor and didn’t show much expression when we talked, so those rare times when she smiled always looked especially beautiful.

“Alright then, for real this time… Let’s head home.”

“Let’s do that.”

And so, Hasumi and I walked part of the way home together. After we parted ways, I went straight home.

“I’m home.”

“Welcome back! Summer break starts today, huh?”

“Yeah, I think I’ll be home pretty much all day during summer vacation, so I’m looking forward to spending a lot of time with you, Nee-san.”

“Geez~! Me too, Tsumugu~!”

My big sister said that with a happy smile on her face. As we stepped into the living room together, I suddenly remembered something I should tell her, so I brought it up right away.

“Oh yeah, Nee-san. I’m going to the fireworks festival with Hasumi this year. Would you like to come along too?”

“…Huh, me?”

“Yeah. We always go together every year, so I still want to go with you this year too.”

“I… Hmm…”

She looked conflicted for a moment, but then quickly smiled and said.

“Onee-chan is fine! You two classmates go and have fun together!”

“Eh, really?”

“Yeah! But, make sure you enjoy the fireworks with Sumire-chan properly, okay? If you don’t, I’m gonna get mad when you get back.”

“O-okay, I’ll definitely enjoy it.”

“In that case, I have nothing else to say! I’m satisfied with that! I’ll go get dinner ready now~”

With that, Nee-san walked off to the kitchen. Something felt off.

That side of her just now… It was the way she acted when she was holding back what she really wanted to say. Even if Nee-san had something on her mind, she usually prioritized me and kept it to herself. Which meant… Maybe Nee-san actually wants to go to the fireworks festival with me too, but she was holding back for some reason? To think she’d give up going to a fireworks festival we’ve gone to together every year, even though she still wanted to go… I couldn’t even begin to imagine what reason she might have.

Then, the next morning… I was determined not to slack off from the very start of summer break, so I woke up early. As I passed through the living room to go get a drink from the kitchen, I saw something.

Nee-san was holding a yukata with a sad expression on her face, and she placed it into a cardboard box.

“……”

After she stored the box away in the storage room, I started thinking hard, trying to figure out how I could bring back that bright smile of hers.

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Chapter 25:  Meeting Up with Hasumi

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“We’re going to see the fireworks! It’s exciting, isn’t it?”

“Totally!”

“I wonder if they’ll have those flower-shaped ones?”

“Those are so cute! I hope they—”

A crowd of people in yukatas passed right in front of me—groups of friends, couples, families, all here together. The reason for this was simple: today was the day of the fireworks festival, the biggest event of the summer and I was standing right at what could be called the entrance to the venue, just as the festival was about to begin.

“One minute until the meeting time…”

The person I was meeting was Hasumi. We had promised to go to the fireworks festival together, so naturally, we were supposed to attend it together. The last time we went out on a day off, Hasumi had arrived at the meeting spot five minutes early. But today, with only one minute left until the agreed time, she still hadn’t shown up. To be fair, there was no rule that said she had to arrive early, but knowing Hasumi’s personality, I found it odd that she hadn’t arrived yet.

“…”

Maybe something happened? Hasumi had very striking looks, and it was entirely possible she might have gotten caught up in some kind of trouble. As that worry gnawed at me, the clock struck the exact meeting time—and right then, Hasumi appeared in front of me, dressed in a yukata.

“T-Tsunagi, sorry, I’m late!”

“Hasumi, thank goodness… You’re not late, you arrived exactly on time.”

Relieved that she was safe, I answered her calmly.

“Yeah, but still…”

Hasumi looked a little awkward, but at that moment, I was more captivated by how she looked in her yukata than by anything else. The yukata she wore had a floral pattern in a red and orange gradient spread across it, with the rest of the fabric in white. It evoked the image of autumn maple leaves and upon closer look, even her earrings were shaped like momiji leaves today.

I pulled my attention back from her yukata and looked at Hasumi herself, then told her what I honestly thought about her outfit.

“That yukata really suits you, Hasumi. You look great.”

“R-Really…?”

“Yeah, it suits you so well it’s almost unreal.”

“Hearing you say that makes me really happy.”

Saying that, Hasumi blushed. Her hairstyle looked the same as usual, but something about that felt so her—and it filled me with a warm feeling on the inside.

“By the way, Tsunagi, you said ‘thank goodness’ when you saw me earlier… Did something happen?”

“It’s nothing like that. You showed up exactly on time, so in hindsight I was just worrying too much. But, knowing your personality, I thought you’d arrive early, and when you didn’t, I started to think maybe you got caught up in some kind of trouble or something.”

“I see… Sorry for making you worry. But, wait—can I just say one thing? The reason I showed up right at the meeting time is actually my big sister’s fault.”

“Your big sister…?”

When I asked that, Hasumi nodded and spoke with a slightly irritated expression.

“When I told her I was going to the fireworks festival with you, she was like, ‘You should wear something that shows your legs,’ or ‘Open up the chest area a bit more’—well, not that exactly, but… Anyway, it’s all her fault!”

At first, the noise of the crowd made it hard to catch what she was saying, but the gist was that Hasumi’s sister had caused the delay, which led her to arrive right on time.

“I got it. But I wasn’t bothered at all to begin with. You showed up right when we planned. I don’t have any intention of blaming you, Hasumi. So let’s just enjoy the fireworks together.”

“Tsunagi… Yeah. Thank you.”

“And also…”

I gently touched the maple leaf earring on Hasumi’s right ear as I spoke.

“You’re wearing momiji earrings today. It’s different from your usual stylish look—it’s more on the cute side. But when I see them together with your yukata, it all feels well coordinated and still looks stylish. That’s really impressive.”

“C-Cute… Uh, y-yeah, I did pay a lot of attention to making sure everything matched, so I’m glad you noticed… C-Cute… You weren’t talking about me, right? You were talking about my outfit, right? B-But, saying that while touching my earring this close is…”

“Hasumi?”

“S-Sorry! It’s nothing, really. Nothing at all!”

“…Alright.”

I took my hand off Hasumi’s earring and looked at her face—only to see her cheeks were still flushed red for some reason.

“Shall we head into the venue?”

I turned toward the festival and took a step forward—but Hasumi grabbed my arm to stop me.

“Wait.”

“What’s up?”

When I turned back to her, Hasumi averted her gaze and said,

“There are so many people… We might get separated, so… Is it okay if I hold your hand?”

“If that’s the reason, then hold my hand as much as you want.”

I held out my right hand toward Hasumi. She gently placed her hand over mine, and the two of us entered the fireworks venue hand in hand. She probably just didn’t want to get separated, but it felt like Hasumi was holding my hand just a little tighter than necessary.

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