After Dazai had left the port mafia at the age of 18 due to his friend Odasaku’s death, he made a promise to become a better person, leaving everything and everyone behind. He joined the Armed detective agency in order to reconcile and make Oda’s wish true, but little did he know he would be crossing paths with his not so favorite executive. While they were on the same scale of annoying as chuuya, it seemed like he couldn’t help but think of it as worst than interacting with chuuya.