Izuku Usagiyama is the son of the no.5 Pro hero Miriko When Miriko had Izuku his father was happy as he finally had a son, hoping to have Izuku inherit a strong quirk. If he was being honest he never actually fell in love with Miriko and he despised her quirk.When Izuku's father finds out that his son has indeed got the same quirk as his mother he leaves then now Izuku and Miriko have to fend for themselves.