Meeting Ning Ning was not Hanako-kun's first relationship. There was another person before Ning Ning, a girl who was extremely brilliant despite her short life span. He would always remember her name - Tian Hai Kong Yao. This was the only thing he could do for her.
Demining: It's not HE. I may write BE later on. After all, only humans who are close to death can see Hanako. Kong Yao is a normal human being. There is no biological mother to trick her. It is a normal slow-burning story. Babies who can accept it can read it.
Intention: Before Ning Ning, Hanako had also become attached to someone.