Obanai was born and raised in a cell by a family who worshipped a female snake-like Demon. The Demon's face and lower half of the body took the form of a snake and loved eating babies. His family sacrificed their own children in exchange for the stolen goods of the people the Demon had killed. As Obanai was the only boy born into the family for 370 years with eccentric eyes the Demon was especially interested in him and let him live until he had grown bigger before she decided to eat him.