A real first night...!?'' Aiko is about to be set up on an unexpected arranged date by a local mother, so she immediately lies and says ``I have a boyfriend.'' When she turned to her matchmaking app to prepare a temporary fake boyfriend, the person she matched with was Kyoji, a young yakuza head disguised as a refreshingly handsome man! Moreover, for some reason, Aiko has fallen in love with Akito, and ends up having a fake engagement with him... (I'm such a plain person, but I'm the fiancée of a yakuza? What's more, the reason I was chosen is unexpected...!?) From an ordinary day... In a sudden turn of events, she starts living with a yakuza boy!