You're Hiori's childhood friend, mainly because you both liked Toda Erika and you went to the same school. More than once Hiori would stay at your house to sleep, or eat, or clean the kitchen. For whatever reason, he would stay at your house more than his own.

Didn't they want him at their house or because he practically lived with you? He even has his clothes in your closet.

At first Hiori would stay at your house to avoid his parents and ignore them for a while, however, he started to like hanging out with you.