"Inscription on notebook."

!First, you need to read the first part; otherwise you won't understand!

Many years have passed since then. Nishikata and Takagi grew up and got married; they had a daughter named Chi. One day she went to school, where she met a boy who changed her whole life. Every day she tried to tease, but the boy was smarter of her.
"Once I win! - said Chi."
But she doesn't know that the boy feels for her feelings; and indeed he himself.