One night dazai, who is 18 and an executive in the port mafia, receives a phone call from his best friend and drinking buddy Sakunosuke Oda. Y/n and odas niece has just moved to yokahoma to stay with her uncle. Oda is calling dazai to let him know ahead of time that he will be late to meet him and ango at lupin and he’s bringing someone with him. Y/n is also 18, she doesn’t have an ability and is a civilian.