WYSM – Vol 1 Chapter 3 Part 2 – My Younger Sister Is a Cosplayer, but Is It Okay to Support Her?

Haa… it’s warm…” (Keitaro)

Under the warm shower, I let out a relieved sigh. After getting drenched from the bucket, I followed Sana’s suggestion and came to the bathroom to take a shower.

At first, I insisted it was fine, but Sana wouldn’t let it go, warning me that I might catch a cold. Considering it’s still chilly despite being spring, it was probably the right call in the end.

Meanwhile, Sana is cleaning up the mess from earlier. Fortunately, the water from the bucket didn’t reach the laundry, so we just needed to clean the floor. 

Sana kept apologizing for her carelessness, but sincr I was the one who placed a bucket filled with water in such a high place, I was also partly at fault. It was a dumb incident which could have been easily avoided.

“Nh…” (Keitaro)

As I take a shower, I let out a deflated sigh. However, it doesn’t mean my mind is completely blank. In fact, I’ve been using this to think about Sana again.

—Sana is acting strange.

Ever since this morning, she’s been behaving strangely—getting up energetically, preparing breakfast, insisting on doing the household chores herself, and telling me to take a break. These are all actions that are completely out of character for the usual Sana. As her family, it sticks out like a sore thumb.

She mentioned something about being a domestic sister, but that’s just a cover-up. There must be a reason behind her actions. Don’t underestimate me. In reality, there’s no such thing as a dense protagonist from a light novel. After showing such an unusual behavior, one can’t just go, “I wonder if something happened?” and leave it at that—no one behaves like that.1

Now, as for the cause of why Sana has become like this…

“…………Yeah, I have no idea.” (Keitaro)

I don’t have any clues. Nothing comes to mind. Why is that?

…I guess it can’t be helped, right? I’m not a dense protagonist, but I’m also not a flawless protagonist who knows everything… Well, in the first place, I’m not even a protagonist. Thinking as if I were the protagonist of a light novel is a common thing for otaku, though.

Setting aside such foolish thoughts, let’s focus on Sana. Based on my six months of experience as her older brother, I suspect that Sana might want me to do something for her. So, she’s trying to appeal to me with household chores and such. I think this assumption is probably correct, but… I don’t know what that “something” is.

If she wants me to do something, I wish she would just tell me straightforwardly. But whether it’s due to shyness or modesty, Sana doesn’t often express such things. Well, she may throw around harsh words, but I think that part of her is quite cute, so I’m fine with it.

“Well, I guess I have to ask directly after all.” (Keitaro)

Having reached that conclusion, I suddenly noticed a sound coming from the direction of the changing room. Looking over, I saw a silhouette on the semi-transparent glass of the door, and there was a gentle knocking sound.

“…Onii-chan, can you hear me?” (Sana)

“Yeah, I can hear you! What’s up?” (Keitaro)

In response to Sana’s voice, I raised my voice such that she could hear me. After mentioning that she finished cleaning up and apologizing for earlier, she hesitantly said that she had a favor to ask.

“A favor? What is it?” (Keitaro)

“…Can you, um, see Sana’s cosplay?” (Sana)


That’s right, cosplay! Sana wanted me to see her cosplay!

On the night of the incident with Yuki, she wanted me to watch her cosplay, but I had to decline. However, with everything that happened afterwards, such as Yuki finding out my identity, Mariel-sama’s buzz, and meeting Serika again, I completely forgot about it and ended up not fulfilling that promise.

Ah, I see. I finally understand now. Actually, it’s entirely my fault for forgetting.

Realizing that Sana had gone through such a roundabout way to get me to remember, I couldn’t help but find my sister adorable. I should have caught on sooner.

Sana enjoys cosplay as a hobby, but she only does it at home and doesn’t participate in events outside. She mentioned that I was the only one she showed her cosplays to. In that sense, I need to properly indulge her whenever I can. I’m looking forward to it.

“Ah, of course it’s fine!” (Keitaro)

I naturally replied with an enthusiastic agreement. Once I’m done showering, it’s time for Sana’s new cosplay debut. Now that it’s settled, let’s get it over with.

Thinking that, I reached for the body soap, but…

“E-Excuse me (ojamashimasu)…” (Sana)

For some reason, the sound of the bathroom door opening reached my ears, and I reflexively turned around. To my surprise, Sana entered the bathroom, and what was even more shocking was her appearance.

She was wearing something like a sailor uniform on top and a school swimsuit on the bottom!? Wait, is this…!?

“……T-This is the new outfit.” (Sana)

In response to my silence, Sana, while her face was turning bright red, uttered those words.

I hadn’t expected her to showcase a new cosplay outfit here of all places! And the outfit itself… it’s, um, quite different from what she usually wears, isn’t it… Isn’t it more sensitive than usual!?

“…H-How is it? Does it match?” (Sana)

“Huh? M-Match?” (Keitaro)

“Onii-chan, you should know more about this outfit than Sana does.” (Sana)

At first, a bunch of question marks filled my mind, but I quickly realized.

“W-Wait, is this a cosplay of Kirara from ‘Marine Heart’!?” (Keitaro)

Upon hearing my words, Sana nodded. 

Marine Heart was a popular mobile game featuring sailor-themed cute girls, and Kirara was one of the characters in the game. Although I secretly played the game myself, I never expected her to cosplay as a character from it. Or rather…

“…Why did you choose to cosplay as a character from Marine Heart?” (Keitaro)

“W-Well, um… Sana saw you playing it, and…” (Sana)

She saw me!? I thought I was playing it in secret, especially because the game had some sensitive elements.

“It was pretty obvious.” (Sana)

“Can’t you refrain from reading my mind!?” (Keitaro)

“Onii-chan, that’s because you’re easy to understand. You always had a big grin on your face when playing.” (Sana)

Oh, seriously…? Someone please kill me.

“I-It’s not an erotic game, so I don’t see any problem with playing it! I’m not going to apologize!” (Keitaro)

“…You’re quick to brush it off. And no one asked for an apology.” (Sana)  

“Anyways, why did you decide to cosplay as Kirara?” (Keitaro)

“Eh? W-Well, um… because she’s, you know, cute…” (Sana)

For some reason, Sana averted her gaze while looking embarrassed. Indeed, characters from Marine Heart typically wore cute sailor-themed outfits, and I had heard they were quite popular in the cosplay community. 

I calmed down and took a closer look at Sana’s appearance.

No matter how you see it, she’s really cute. Seriously. Sana was already a beauty, but somehow, she seemed even more lovely in the outfit. Not to mention, the quality of her cosplay is top-notch, and the fact that she perfectly recreated Kirara’s costume is amazing.

I was surprised when she suddenly showed up in the bathroom, but putting that aside, I couldn’t help but be impressed by Sana’s talent. Man, my little sister is such an amazing cosplayer, I can’t help but want to show off to everyone.

“Yeah, I think it’s amazing. It suits you well, and you totally look like Kirara.” (Keitaro)

As I nodded in approval, Sana smiled happily. While she isn’t particularly expressive of her thoughts, I loved seeing this particular smile that she only shows when cosplaying.

…Well, that’s all well and good, but we’re in the bathroom, so I’m only wearing a towel on my lower body…! Adding to the awkwardness is the fact that my stepsister is in a sailor swimsuit cosplay. I would really appreciate it if she could leave soon…

“…Thank you. Now, Sana will wash your back, so turn around.” (Sana)

“What!?” (Keitaro)

However, instead of leaving, Sana started saying something even more outrageous.

“L-Like I said, Sana is going to wash onii-chan’s back just like in that scene.” (Sana)

“T-That scene? Well, Kirara does have such event scenes but isn’t that a bit too much…?!” (Keitaro)

“…Was that scene really that inappropriate?” (Sana)

“No, it’s not like that! While there may be some slightly suggestive elements, that scene is a crucial moment where Kirara truly opens her heart to the captain for the first time! People who don’t understand that often dismiss Marine Heart as an ‘eroge lol,’ but it’s actually a heartfelt game!” (Keitaro)

“…So, there’s no problem. Now, turn around.” (Sana)

“Huh!? Wh-what a clever leading question…!” (Keitaro)

Dismissed with a cold response, I had no choice but to turn my back to Sana.

…The issue isn’t the scene itself, but rather the fact that we’re trying to recreate it. Yet, I can’t help but feel a strange pressure from Sana, and for some reason, I find myself silently complying with her wishes.

“…I-Is this how I do it? What do you think?” (Sana)

“Well, I don’t really know considering it’s my first time having my back washed…” (Keitaro)

I give Sana a vague answer. While I can feel her earnestly washing my back with the sponge, given the circumstances, I don’t have the composure to offer any coherent feedback.

…Calm down. It’s just an older brother having his younger sister wash his back. But wait, she only became my stepsister just six months ago, right? Ugh, these distracting thoughts…!

“…Um, I get that we’re trying to recreate the scene, but we haven’t done anything like this before. Why the sudden change?” (Keitaro)

In order to maintain my composure, I throw out such a question.

While I’ve watched Sana cosplay many times before, I was merely observing, nothing more. So why now?

“…T-That’s, um, because… Sana thought it would be nice to recreate it since it’s a game onii-chan plays…” (Sana)

Wait, does that mean that this wasn’t something she specifically wanted to do, but rather something she did for my sake?

…Strange. From barging into the bathroom to cosplaying characters from games I play, and now reenacting scenes, her actions are out of character. There must be a deeper reason behind it after all, right?

Oh, by the way, if you’re asking whether I’m happy or not, I’d say I’m really happy, especially because she’s doing it for me! But, that’s beside the point right now!

“Hey, Sana, why are you doing this agai—” (Keitaro)

I turn to ask Sana, but I’m left speechless when I see her.

“…I-I’ll do my best… Because Sana is the domestic type of sister…!” (Sana)

“Hey, Sana!?” (Keitaro)

Sana’s face is bright red, and she’s swaying her head, her eyes seemingly on the verge of rolling back.

…Is she feeling dizzy!? No, it’s not that hot in here! Maybe she’s reached her limit of embarrassment, but if that’s the case, then why did she even start doing this in the first place?!

“Hey, are you okay!? Pull yourself together!” (Keitaro)

I shake Sana’s shoulders while calling out to her. However, perhaps due to the shaking, the towel wrapped around her waist suddenly falls off.

“Ah…” (Both)

We both let out a surprised gasp, our gazes inadvertently dropping downwards and then quickly snapping back up in unison.

Kyuu *faints*

“Sanaaaaaaaa!?” (Keitaro)

And then, Sana collapses—wait, why is this happening!? How did it end up like this!?

I’m left bewildered as I hold up Sana’s limp body. I have no idea how we ended up in this situation. But one thing’s for sure…

…Aren’t lucky moments like this supposed to end the other way around?


“…So, why did you do that?” (Keitaro)

I ask as I dry my wet hair with a towel.

After that incident, Sana quickly regained consciousness, and we both changed clothes before ending up here, facing each other in the living room. 

“If you have any worries or concerns, feel free to tell me. If it’s something I can help with, I’ll do my best.” (Keitaro)

I wanted to know the reason for all of this, so I asked in a concerned way.

…No matter how you look at it, what happened earlier was definitely over-the-top. It was quite cute though.

“…………” (Sana)

However, Sana only shows a troubled expression without giving an answer. …Hmm, this seems to be quite a deep-rooted issue. As her brother, I must do everything I can to support her.

“Everyone has their own worries. Feel free to talk to me about anything.” (Keitaro)

“What do you mean by ‘everyone has their own worries’?” (Sana)

“Why are you giving me that look?” (Keitaro)

“…Haa, fine. Maybe it’s better to clarify things.” (Sana)

Sana sighs and then looks straight at me, before opening her mouth to speak.

“Onii-chan, how do you feel about being buzzed about?” (Sana)

“Huh? Buzzed about? You mean the incident with Yuki and Mariel-sama?” (Keitaro)

“Yeah, the idol and VTuber.” (Sana)

“Why are we suddenly talking about that? We were discussing your concerns…” (Keitaro)

“Just answer.” (Sana)

Sana cuts off my words sharply. Her eyes seem oddly intense… 

“Well, it was definitely surprising. They’re both super famous, so getting talked about by them out of the blue is bound to be confusing.” (Keitaro)

“…Only surprise and confusion? Could it be you didn’t like it?” (Sana)

“Oh, there’s nothing like that. I was surprised, but I’m genuinely happy. After all, they’re both my oshis. Being acknowledged by my oshis is something to be happy about, right?” (Keitaro)

“…Yeah, you’re right.” (Sana)

To my response, Sana lowered her head for a moment, pondering something before asking another question.

“Onii-chan, you met them in real life, right? How was it?” (Sana)

“How was what?” (Keitaro)

“I mean, how were they as people? I heard that the idol was your classmate and the VTuber was your childhood friend…” (Sana)

Sana’s expression seems a bit displeased only when she mentions the parts about being classmates and childhood friends. Anyways, it seems that she’s interested in knowing more about them.

“It’s difficult to describe how it was… Meeting them in real life made me realize that things are totally different from seeing them through a screen. Maybe it feels that way because both of them passionately support me so it feels like our roles are reversed. For example, Yuki usually gives off a cool vibe, but when we met, she was incredibly high-energy.” (Keitaro)

“…Really?” (Sana)

“Yeah, just so you know, I’m not exaggerating!” (Keitaro)

“No one is doubting you. Besides, after watching the videos that led to the buzz, it’s clear that both of them genuinely support you.” (Sana)

Hmm, so Sana watched the videos of those two as well. It’s surprising considering she didn’t seem interested at first.

“…So onii-chan, does being supported by those two makes you want to give it your all?” (Sana)

“Well, of course.” (Keitaro)

I nodded. To be precise, I feel like I have to give it my all. After being publicly supported by my oshis, I need to make sure that I become a streamer worthy of their support so that I don’t let them down.

“…I see. So, Sana has no choice…” (Sana)

As I responded, Sana muttered softly to herself, seeming lost in thought.

…Wait, what are we talking about? This was supposed to be Sana’s consultation, but somehow the conversation has taken a completely different direction. I tilt my head in confusion, and eventually, Sana lifts her head.

“Onii-chan, Sana has a favor to ask.” (Sana)

“Oh, I see. You can tell me anything. I’ll do whatever I can to help. Oh but spare me if it’s about wanting me to stop supporting my oshis because I’m creepy or something.” (Keitaro)

“…Sana won’t say that. Oni-chan will die if she does.” (Sana)

Wow, sister dearest, you know your brother really well. I was sweating a bit, thinking the conversation might head in that direction after talking about Yuki and Mariel-sama, but thankfully it didn’t.

Well, I’m a little concerned about the slightly stern look she’s giving me, though.

“…The favor is for you to come with Sana to a certain place.” (Sana)

“A certain place? Now? I’m okay with it, but where are we going?” (Keitaro)

I naturally ask the question, and Sana, with a gaze filled with determination, responds in an unusually clear tone.

“A place where Sana can show her true self.” (Sana)

TL Notes:

Thanks for reading!

Just so you know, I don’t think it was ever mentioned how Sana knows that Yuki is MC’s classmate and Serika is MC’s childhood friend. Did MC tell her about it off-screen or did she find out via other ways…? Either that or he did mention it and I forgot.

Anyways, looking forward to number 3.

Also, I changed the background color. This is the color of one of the themes I had listed. Let me know if it’s better or worse.


  1. The irony here. And here I thought that our MC was gonna forget about her behavior in the last chapter.
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