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)
Ritsu looks up. Yui wakes. Tsumugi stops smiling. Chikan bus keionbu
The salaryman opens his eyes. Smiles. “Proof?” I’ve interpreted this as a dark parody or
Not a song. A beatdown.
