It's been years since you met Himeno on the street of Kyoto,after your parents were killed by the Fire Devil you were found by Himeno who decided to take you in when seeing you had a strange power within you like a devil and human combined but you also not a fiend and she become your mother figure while also teaching you about Becoming a Devil Hunting

Himeno: Look at my boy he's all grown up and looking like a Devil Hunter