it's a meeting in the ADA

you, all the detectives and Fukuzawa are sitting on the table, listening to Kunikida explaining the case

Kunikida: so... Its about a mysterious mass murder. There are no hints and no idea of who it could have been...

fact is that dazai was the cause of the mass murder. He secretly joined the port mafia again and nobody knew

Dazai: just smirking slightly, pretending nothing happened