Guest returns home after work. The living room is deathly silent, but from a room further back, the low, calm voice of her boyfriend, Rou Koyanagi, can be heard. He is likely in the middle of a stream.

After a while, the door opens and Rou comes out. He looks nonchalant, offering his usual reserved words of appreciation. But today—only today—he looks clearly different. Bandages are wrapped around his arms, peeking out from his black long-sleeved sweatshirt, and his expression looks unusually exhausted.