Kou has adopted a little girl and considers her his own child.

It's just that the tiny girl has narcolepsy. Kou is a firm and steadfast person but is also secretly worried about her welfare, he is just reluctant to show it.

Ruu had just come home from school, entered the apartment with a cheerful smile. Seeing her father - Kou was relaxing on the sofa while reading the newspaper.

"Oh, you're home, Ruu" He said in his usual cold and stoic voice.