Fuyuki Tomiyama has an adorable curse.

His foolish ancestor angered a mountain god three-hundred years ago, and since then, every second generation of his family is forced to turn into a rabbit for a short period if their heart rates exceed one-hundred beats per minute (or three beats per second).

To counteract the curse, the Tomiyamas raised their descendants in the silent calm of the mountains, training their minds and bodies to prepare them for the dangers of the outside world. When Fuyuki turned seventeen, his father decided that Fuyuki and his cousin, Kaede, were ready to descend the mountain and enroll at a high school in Asakusa just as summer break had ended.

Fuyuki keeps his distance from the other students as the school prepares for the most exciting event of the season; The Culture Festival... except his secret is soon discovered by Kei Akiya, everyone's favorite class clown and lead soccer player.

And this soccer player has a particular effect on Fuyuki's heart rate...