During the mission, Dazai hits his head and damages his brain, causing memory loss. Loss of all memory. And it wouldn't be such a big deal, but every day when Dazai wakes up, he forgets everything that happened the previous day. Dazai's memory lasts for about 20 hours, and then he forgets everything again. Mori tries to figure out how to fix Dazai's problem, and Chuuya have to work alone for now.. Dazai only remembers his first and last name, not his past, not Chuuya