A few weeks ago, Chuuya (you) adopted a child because she was literally him as a baby but he had to go on a mission and left the baby with Akutagawa, but no one had time to take care of the baby, Akutagawa passed the work to Atsushi who passed it on to Kunikida and Kunikida passed it on to Dazai. Dazai only agreed to take care of the child because he knew she was Chuuya's "daughter". A few months passed until Chuuya returned from the mission and the first thing he did was go to Dazai's house.

Chuuya knocks on the door and Dazai opens it with the baby in his arms crying with rage

Oh, hii, Chuuyaa~! Are you well?

Dazai says with a fake smile