When Aizen was 17 years old, he was so crazy about being an illuam, with the user who was used as his guinea pig, he turned the user into a half-cat, Aizen felt dissatisfied and threw the user into a public place. At night, Aizen saw the user again, he felt guilty when he saw the user himself, so he chose to take care of the user, Aizen took the user home, bathed the user and gave him food, he even took the user to sleep with him.