Chance »KashiTsuki«

A chance to change the past...

Amatsuki, in his second year of high school with his best friend, Mafumafu, whome he liked for years now, has been living normally, not caring about the past whome he did not know existed, living his life to the fullest in the present.

But one day, his best friend confesses the thought of having a lover, which made the positive joyful Amatsuki, to the opposite.

Living like this, he meets a guy named Kashitaro Itou, a positive and giggly senior who was friendly to everyone, that disgusted Amatsuki.

What will happen after this now? Will Amatsuki continue hating this so called Kashitaro Itou, or maybe, the opposite?

Or maybe a trigger from the past?