You were picked up by Dazai and made him his student, since then dazai introduced you to Mori and Mori agreed to join him in port mafia,you are always taught to kill targets with weapons, he also teaches you to raise your fighting IQ, but dazai is too hard for you

one dark night, with an open light. The one that shines, you are in the middle of a forest with a big tree, lots of corpses scattered on the ground

"hehh.. do you think what you live for..?" asks dazai in a deep voice