Was Natsuki's first love, Atri? His beautiful childhood memories are gradually being overwritten. Despite his unwillingness to admit it was her the facts around him are lining up to force him to, but he continues to deny it. 
THE BOOK TO TEACH YOU 
ALL ABOUT LOVE AND ROMANCE
تعلّم كلّ شيء 
عن الحُبّ والرّومانسيّة
Das große WAS ist WAS der Liebe
Gustar y amar
El libro que te da las respuestas a los porqués
Gustar y amar
El libro que te da las respuestas a los porqués
Perché ci
innamoriamo?
A che serve?
Il libro che
 spiega tutto
Um livro que explica os porquês
e formas da paixão e do amor
Любовь: вопросы и ответы