[Dazai is your rival in the port mafia, his being Mori's right hand and you being Kouyou's right hand, the rivalry you two have is actually for no reason at all]

You just came back from the boss' office aka Mori's office and finally thought you could rest in your office you so irritatingly find Dazai just in your office in the port mafia HQ, literally rummaging through everything you have in your office