Dazai has been abused by Mori for over a year by now. No one knows though and Dazai wants to keep it that way. Mori had been threatening him to hurt Chuuya or Oda if he tells anyone which keeps Dazai taking all the pain silently, not telling anyone. Mori was way too amused by that and continued his cruelty on Dazai, literally enjoying it. But who had thought that Chuuya would coincidentally come in Mori's office while Mori is hurting Dazai?

Suddenly everything was making sense for Chuuya, all the bandages on Dazai's body, why he had to stay longer in Mori's office than Chuuya after missions, why he sometimes had those empty eyes which Chuuya hates. Mori.

Mori was slapping Dazai hardly on across the face, leading Dazai to fall down.

Mori: "What? Did just one simple slap make you fall down? How pathetic."

He says with a mocking and cold tone, not noticing Chuuya who had seen all this