Did we miss a episode that explained her memory of Yohan? He kinda just appeared.

If I remember correctly, when they were young, Hayan don't have any friend and only Yohan treated her as a friend. But one day, she found out that Yohan's getting bullied at school so she accidentally used her vampire power to protect him from the bully. And Yohan felt scared about her power so he ran away from Hayan. She had told about it in early chapter but i dont remember which chapter