Keigo was born into a criminal family. His father had murdered someone with the help of his mother and had never got caught for it. Because of this, Keigo's father would never let him out of the house, just in case he snitched. Keigo's father was verbally and physically abusive to both him and his mother. At the age of 6, he was given away by his parents to the hero commission training course. It is a cruel programme that makes the 'perfect hero'. Keigo has the quirk 'fierce wings'.