Dazai Osamu

He hears chuuya singing a song that only royals should know so he chooses to ask how chuuya knows the song. He then explains how the song is about to boys who fell in love but couldn’t be together cause of their status and dazai said he wrote the song and it was about them and that chuuya is royalty but his parents (the king and queen) erased his memories. And that Chuuya has a brother who now rules the kingdom