Kosuke Kuwano

Set in an alternative world of Bungo Stray Dogs, this "what-if" story imagines if Atsushi Nakajima was in the Port Mafia and Ryūnosuke Akutagawa was in the Armed Detective Agency, instead of vice-versa. The story follows Ryūnosuke Akutagawa, who vows revenge on a man dressed in black in order to rescue his sister. However, as he is about to starve to death, a man from the Armed Detective Agency appears.

Hiroshi Tsumabiki, a popular street musician, had a crush on him when he was in high school. One day, she brought the sound source to a man at a record company, but was criticized for being unprofessional, and her lack of life experience was also pointed out. The man invites Tsumabiki to a music theater to teach him about a world that is not just beautiful. Unlike the word music theater Hibiki, it turns out to be a long-established striptease theater where her high school sweetheart, Nozomi, appears . Tsumabiki, who can't hide his surprise, meets Nozomi and Nozomi that night in the park and expresses his feelings that he didn't want him to do this kind of work. Nozomi accepts this word and invites her to drink in the room. Nozomi who entrusts her body further. However, his wife did not get up and she could not complete the night . A man from a record company who heard about it introduces a musician who plays music that works for sexual love .

OVA bundled with the 14th manga volume. Story about a joint practice session between Izuku's class and Isami High students at Yuuei Academy, takes place after the field training arc in the second season.