Sōichirō Nahashi, who is always referred to by his surname, is the guardian of Lucia, and he loves her as if he were her real father. Before Lucia was born, Nahashi was studying to become a mage, along with Lucia's mother Lilith and Lucia's father Lucif. Nahashi is an older gentleman with grey hair that goes just pass his shoulder, a mustache and goatee. He is good and lovely father, kind and caring person. Being wise due to his age, Nahashi can give good advice or help with delicate situation.