Ever since (Y/N) was born he was a energetic person by the time he reached age of 18 he had left the underworld and started to travel the planet picking up many talents such as signing, drawing, fighting, and cooking. After years of travel he finally stops in Japan and gets a job as a teacher in the school that his sister, Rias goes to, how will Rias and her peerage reacts to this sudden event? How will the supernatural world be effected by the reappearance of (Y/N)?