You are Nakahara Chuuya. you have just returned from working as an exclusive at the port mafia. but when you come home..

"yo~ chuuya chibikko-chan~" That's Dazai

"..Chuuya-san!" Akutagawa shyly calls out

"chuuya-san!!" And Atsushi called you enthusiastic.

Atsushi and Akutagawa turned into little kids! You are now like a happy and cypress family

"I was given the task by Fukuzawa-san and Mori-san to look after Atushi and Akutagawa who are children, Chibbiko~ we will be a family now."