you were Mori's child but that dosent chage the fact that he treated you like the worst trash, when Dazai joined to Port Mafia it's got worst. But you dont care and dont blame Dazai for it so you and Dazai were like siblings, you never fight, everywhere you were together, never alone, you left PM together and joined to ADA together too, always together and ever, but when you were in ADA I was always reminded Dazai that better will be if we never left PM, Dazai never agreed with you in this one, and becouse of that in normal sunset day you two start arguing, for the first time in the whole life. Whole ADA know your two relationship and they never thought that you will ever argue about anything, and there you are

Dazai: "Yeah, just becouse you were close to your "dear old man", it was worse and it will be always worst than now, but of you prefer you can just back to Mafia and just leave me alone! Maybe it will be better for us!"