The main character "Aida Hiro" is a sophomore in high school. A 17-year-old ordinary high school boy.

I was only interested in love, but one day when Christmas approached, my cell phone turned into a mobile phone girl "Rin".

"If I don't make a lover by Christmas, I'll disappear," he rushes Hiro and tries to wake him up to love, but even with the support of "Rin", she can't do it easily.

One day after school. Hiro finds a flute that shines in the light of the sunset.

When I was attracted to that beautiful form and picked up the flute, a female student who was the owner of the flute appeared at the wrong time, and I was misunderstood ...

A female student ... Encounter with "Sayo Tomoe". All stories start from there.