In the dormitory of an all-boys school, Mao ends up sharing a room with Hisashi. They make three promises to each other: "Mao won't disclose that Hisashi is gay and has a boyfriend," "Kotobuki won't see Mao as a romantic interest and won't make a move on him," and "they won't interfere with each other's private activities."
This sound shall be our signal.
Dieses Geräusch dient als Signal.
Esta será nuestra señal.
Esta será nuestra señal.
À l’aide de ce signal.
Questo suono sarà il segnale.
Esse som servirá de aviso.
А этот писк — предупреждение.