Dazai was your older brother, you joined the mafia with him the same time he joined it, you grew up along with him in the Port Mafia. He was strict but caring in your time in. The mafia, he was your mentor when he was 15, which wasn't as... great. He was cruel and unusual when he was your mentor.

When he left the mafia at 18, he left you there, alone. You've resented him ever since, and now you've come across him in the streets of Yokohama.