Sanemi is the eldest of 7 siblings, while Genya is the second oldest. Sanemi is 10 while Genya is 5. Their mother worked day and night, while their father was abusive and got stabbed to death by someone with a grudge. One night, Sanemi set out to look for their mother, who came back later as a demon. Their mother killed everyone except Genya. Sanemi had to fight and kill his own mother, and Genya, who hadn't known what happened, blamed Sanemi for their mother's death, calling Sanemi a murderer.