Just as Hara Kei was testing the pool water with his fingers, a sudden splash broke the silence.
A dark figure dove straight into the pool.
It was Teacher Zesen.
Once she snapped out of her initial shock, she swiftly stripped off her jacket and track pants, revealing the athletic lines of her body and the simple swimsuit beneath.
There was nothing seductive about it — she wore a plain racing swimsuit, the kind that covered her entire body snugly, exposing only her arms and long, toned legs.
Like a fish gliding through the water, she swam gracefully, her strokes sharp and efficient — exactly what one would expect from Saint Eden Academy's swimming instructor.
She quickly reached one of the floating objects on the water's surface — a dark blue school swimsuit — grabbed it, and returned to the edge of the pool.
The members of the Lambs' Club gathered around, observing the recovered swimsuit with focused expressions.
"…Looks brand new," murmured Shinomiya Kaguya, pinching the fabric delicately between her fingers. "No name tag… and no stitching marks either."
At Sakurajima High, every student's swimsuit used in class was embroidered with a white name tag on the chest.
These, however, had no such tags — nor any traces of one ever being attached.
That meant these swimsuits had never been used, and weren't just old ones with tags ripped off.
"Zesen-sensei, are these the ones your club reported missing?" asked Chika Fujiwara, peering toward the teacher still treading water.
Zesen-sensei frowned slightly, looking troubled.
"I'm not sure. Before they're issued, all the school swimsuits look exactly the same."
She turned toward the other floating bundles. "If we collect all of them and check the total count… maybe we'll know for sure."
"I see…" Fujiwara murmured, deep in thought.
Then, with a sudden burst of resolve, she picked up a few of the swimsuits and held them against herself as if measuring the size.
Zesen-sensei blinked, wide-eyed. "Fujiwara-san, what are you doing?"
"To uncover the truth, sometimes you have to take direct measures," Fujiwara said, her tone unusually serious. Hara Kei could tell she wasn't joking — she was determined to get to the bottom of this case.
Fujiwara was usually cheerful and kind-hearted, a bit mischievous at times, yes — but when it came to serious matters, she could be incredibly focused.
And right now, this situation could be either a harmless prank… or something far more disturbing — the work of someone with darker intentions.
Her sense of justice wouldn't allow her to sit back and do nothing.
Realizing what Fujiwara intended, Shinomiya hesitated for only a moment before asking, "Can we drain the pool?"
Zesen-sensei winced. "This pool's huge… The cost of refilling and reheating the water isn't small. The girls have matches coming up, and if we drain it now, it'll cut into their practice time…"
"I see." Shinomiya didn't wait for her to finish. Instead, she began rummaging through the recovered swimsuits as well.
"Then give us waterproof sleeves," she said, gesturing precisely. "Aside from the swimsuits, there's still that black stuff stuck to the bottom of the pool, right?"
"If draining it isn't possible, then we'll just film it. We'll use waterproof phone cases, dive down, and record whatever the culprit left for us. Maybe there's a message hidden in it."
"Oh!" Zesen-sensei's eyes lit up in realization. She climbed out of the pool and hurried toward the locker room.
Fujiwara and Shinomiya followed, each grabbing a swimsuit that fit their size.
Before heading off, Fujiwara turned toward Yukinoshita Yukino and Hara Kei.
"Yukinon's still sick, and Hara-kun's a guy — you two should stay dry," she said, hugging the swimsuits to her chest. "But we'll be counting on you to handle the detective work side of things, okay?"
She smiled, nodded once, and disappeared with Shinomiya into the changing room.
Soon, the vast indoor pool area was left with only Hara Kei and Yukinoshita Yukino.
"...What do you think, Hara-kun?" Yukinoshita asked softly.
There's definitely something off about this, he thought.
He almost said it aloud — but if the other person didn't catch the joke, the timing would just fall flat. So he simply shook his head.
"I can't quite figure out the culprit's motive yet," he said finally. "There's not enough evidence to draw conclusions."
Yukinoshita's eyes brightened. "So… you do have a suspect, then?"
Hara Kei neither nodded nor denied it.
He just stared at the pool before them — the floating new swimsuits, the gently steaming water, and the dark shapes clinging to the pool's bottom.
Together, they formed a surreal and eerie tableau.
And Hara Kei gazed at that strange, distorted mural — trying to decipher the artist's intent hidden beneath the surface.
Later that afternoon—
"Hehe~"
Fujiwara's usual smile had returned, brighter than the sunlight filtering through the gym's glass windows.
As for why she looked so happy?
Simple — she was currently piggybacking on Hara Kei's back.
They'd retrieved all the swimsuits from the water, dove to the bottom to investigate the dark substance, and even photographed everything for evidence.
With only half an hour of lunch break to work with, it had been exhausting. Without Shinomiya and Zesen-sensei helping, Fujiwara might not have made it back to the edge of the pool at all.
But in the end, their hard work paid off.
They confirmed the nature of the black material and captured the entire pattern it formed on the pool floor.
And as for Fujiwara's "bonus reward" — that would be this very moment.
She leaned her upper body just slightly, resting more of her weight against Hara Kei's broad back.
Her nose caught the faint scent of his shampoo — or maybe laundry detergent — she couldn't tell which. All she knew was that it smelled really good.
Her legs felt weak — but not from fatigue.
Right now, she wished more than anything that the distance between the pool and the club building could stretch on forever… just a little longer.
Fujiwara quietly tightened her arms around Hara Kei's neck.
The members of the Lambs' Club were on their way back, having promised Zesen-sensei they'd uncover the truth soon.
Lunch break was almost over; they hadn't even eaten yet.
"The black stuff on the pool floor — it was some kind of fabric tape?" Hara Kei asked.
"Mm." Shinomiya nodded tiredly, leaning on Yukinoshita for support as they walked.
She pulled out her phone, intending to show him the pictures they'd taken. Her hands trembled from exhaustion, and she accidentally backed out of the camera app.
An ugly, familiar icon appeared on the screen — one that Hara Kei had seen just this morning when Fujiwara showed him her phone.
That mobile game again…
Don't tell me this thing's popular across the entire school now.
As he pondered that thought, something like lightning flashed through his mind.
Hara Kei froze mid-step, completely lost in thought.
He didn't notice Fujiwara's small, silent movements behind him.
Nor did he see Yukinoshita glance at him, cheeks puffed slightly in quiet annoyance, as if refusing to admit she was curious about what had just stolen his attention.
..
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