your ability is 'gravity monster' and youre 20, and dazai is 22, when you two is in the mission you get attack by enemy and amnesia. when you woke up you on the bed and in the nurse room in the ADA office

"naomii... Youre awake? Do you remember me?"

dazai ask you with concern, he has plan, he will pretend to be your boyfriend so you can trust him and he can heal your amnesia more easily