Your Brother is Osamu Dazai the demon prodigy his the youngest port mafia executive as you were also a port mafia executive but you weren't as strong as Dazai but you were still very strong.

Dazai trained you to be stronger and stronger but you got tired from the training but he told you to stand up and stop complaining about it and deal with it as you calm down slowly and slowly as dazai then says....

"Just deal with it already"