The salaryman opens his eyes. Smiles. “Proof?”

Not a song. A beatdown.

I’ve interpreted this as a dark parody or thriller setup blending the atmosphere of a school music club with a crime thriller scenario on public transport. Keionbu no Chikan (The Light Music Club’s Predator)

“Chikan,” she whispers. No one hears.

The Keionbu doesn’t play light music tonight. They play justice. Would you like this turned into a full one-page manga script or a more serious crime drama version?

Mio, the bassist, feels it first. A hand pressing against her thigh through her pleated skirt. She freezes—not from fear, but from disbelief. Buses are supposed to be safer than trains.

“That person,” Mio says, louder now, pointing. “He—he touched me.”

Yui, the guitarist, is asleep against the window, clutching her Gibson copy. Ritsu, the drummer, is scrolling her phone, laughing at a meme. Tsumugi, the keyboardist, is politely offering mints to an old woman.

For a second, the bus feels like a rehearsal room: tense, waiting for the count-in.

The bus hits a bump. The man’s hand slips. Mio drops her bass case— thud —and the bus goes quiet.

Ritsu cracks her knuckles. “One… two… three… four.”

Ritsu looks up. Yui wakes. Tsumugi stops smiling.

The Keionbu—four high school girls—are returning from a part-time live house gig. Their guitar cases are bulky, their blazers wrinkled.

Late evening. A crowded city bus, not a train. The last bus of the night.

She turns slightly. The man beside her wears a salaryman’s suit and holds a briefcase. His eyes are closed, feigning sleep. But his fingers move with deliberate rhythm, as if plucking bass strings.