One lazy Sunday in June, Yukio came back with breakfast and a bag of groceries.
Lately, he'd been helping Nanase with extra training almost every day, and maybe she'd started feeling guilty about taking up so much of his time—because she'd gotten into the habit of buying him breakfast nonstop.
Today, after training wrapped up, Yukio went to take a quick shower like usual. When he came out, he'd stopped her and told her that the fridge was empty, so he'd handle the shopping and grab breakfast himself from now on. No need for her to keep fussing over him.
Except the moment he pushed open his dorm door—he caught Nanase, the always-so-upright underclassman, acting like a full-on burglar.
The instant she saw him, she jolted. With panicky speed, she balled something up and shoved it into the pocket of her pleated skirt.
Even Yukio didn't get a clear look at what it was.
"S-Senpai, y-you're back!" Her pitch shot up. She looked like she was two seconds away from short-circuiting, stuttering so hard she might as well have "I DID SOMETHING" written across her face.
Yukio stared at her, baffled. "Nanase…?"
"I—I—I need the bathroom!" she blurted, refusing to meet his eyes, then bolted into the shower room.
Click.
She locked the door.
Yukio stood there with a huge question mark floating over his head.
After a couple months around her, he knew Nanase's personality inside and out. If anything, she was a golden-retriever type: earnest, rule-following, always trying her best—just… occasionally missing a few screws and turning adorably airheaded at the worst possible times.
Stealing? From him? He couldn't picture it.
But this suspicious behavior? Yeah. It made him curious.
He scanned the room. Nothing looked missing. Then his eyes drifted—
"Huh…?"
His workout clothes were hanging on the balcony rail.
Those were the ones he'd only taken off after morning training. Had she… washed them?
Yukio frowned. Something still felt off, like one tiny piece didn't match the picture.
…
Meanwhile, inside the locked bathroom, Nanase was basically melting down.
Her face blazing red, she frantically pulled the black cloth bundle out of her skirt pocket and unfolded it with shaking hands.
Square-shaped. High-quality fabric. The kind you could tell was expensive the second you touched it.
Men's boxer briefs.
And right in the middle, the fabric was… subtly stretched, like it had spent a long time hiding something that absolutely refused to be ignored.
"Uu… what do I do…" Nanase whimpered so quietly it was almost a breath. Her bright blue eyes shimmered with tears, while her cheeks burned hot enough to fry eggs.
If you had to describe it, she looked like a natural ruby—heated from within—still beaded with morning dew.
"Senpai… Yukio-senpai is going to find out and think I'm… a pervert. I'm totally a pervert…" Her voice wobbled, full of embarrassed misery. "How did this even happen…?"
She wasn't trying to be creepy.
She'd just felt like she'd been causing him trouble—so she wanted to do something small to repay him. Breakfast alone didn't feel like enough.
Then she'd spotted his sweaty clothes after he left, and thought, Fine. I'll wash them. That's normal. That's helpful.
Shirt. Shorts. Easy.
Then she'd reached the boxer briefs.
And her brain had immediately blue-screened.
If she picked them up and washed them like normal… she'd die of embarrassment.
But if she left them… that felt like quitting halfway, and Nanase didn't quit halfway.
So the diligent, painfully earnest underclassman got stuck in a ridiculous moral wrestling match for way too long—thinking about how hard he trained, how hot it'd been lately, how he came back sweaty because he was spending time teaching her—
Because of me…
And finally, cheeks on fire, she'd forced herself to decide.
I'll wash them. I'll be an adult about it.
She'd reached out with the hands of a woman determined to be brave—only for Yukio to walk in at the absolute worst possible moment.
Nanase had panicked, stuffed them into her skirt pocket, and sprinted into the bathroom.
And now that she'd had a second to process it, she realized the truth. She'd wasted so much time overthinking that if she'd just decided faster, she would've been done already and none of this would be happening.
"No. T-This is wrong," she muttered to herself, trapped in the bathroom with her shame. Her serious nature refused to accept her own instinctive escape. "I-I need to explain and apologize to Yukio-senpai."
Talking out loud gave her a tiny burst of courage.
But the second she turned toward the door, her imagination betrayed her.
She'd step out, face Yukio, and—what? Unfold his boxer briefs in front of him like she was presenting evidence in court?
That mental image alone nearly killed her.
"Th—That's… way too embarrassing…!"
Thunk!
Nanase smacked her forehead against the bathroom door, face scarlet. "That's social death. Total social death. He'll misunderstand me for sure!"
"Uu… I wanna disappear…"
Outside, Yukio's attention snapped to the bathroom when he heard the impact. "Nanase?"
"S-Senpai, I'm so sorry!" Hearing his voice—like he was worried—shattered her last bit of emotional defense. The guilt hit too hard, too fast.
Now Yukio was really lost. He walked up to the door. "What are you even—"
Click.
Nanase couldn't take it anymore. She unlocked it and stepped out, eyes wet, cheeks burning, then bowed so deeply it looked like she was trying to fold herself in half.
Both hands extended forward like she was offering a sacred treasure.
His boxer briefs.
The air went dead silent.
Nanase stayed bowed, refusing to look up. In her head, she was already bracing for impact.
Scold me, senpai. Yell at me. I won't argue. I deserve it.
Just… please don't abandon me. Please don't stop training me—no, that's greedy. That's way too greedy…
If he never wants to see me again after this, that would be totally fair.
But why was it so quiet?
Why wasn't he saying anything?
Unable to stand the silence, Nanase finally lifted her eyes.
Yukio was frozen stiff, face completely locked—like his soul had briefly left his body and hadn't returned yet.
"C-Cough—cough!" Yukio's brain stalled so hard he actually took a half-step back on instinct.
Nanase, without thinking, took a half-step forward.
Yukio—like some exhausted parent trying to talk sense into a kid—ended up blurting out the most awkward "responsible adult" lecture imaginable.
"N-Nanase… look… how do I put this…" He sounded like he was improvising the words as they fell out of his mouth. "Girls your age… it's normal to get curious about certain things. Totally normal. Butb some things aren't… appropriate."
Nanase's face exploded redder. "N-No—no no no! That's not it! Senpai, please—listen to me! I can explain!!"