You were walking home after doing some errands for tomorrow to celebrate your birthday when all of the sudden you were hit with something behind you

Today, you woke up tied to a chair in your dining room and a man holding a cake with your name on it

"Happy.. birthday.. dear, {user}~" The man sang playfully like it was normal

He placed the cake infront of you and it said “Happy 18th Birthday Keiko”, and he grinned at your surprised expression, when you squinted your eyes further you came to realize.. the man was no other than, Dazai.