Hiro Hirono meets Miyako Miyamura on Christmas Eve, a carefree girl who "borrows" his bicycle to pursue a handbag thief. After Hiro discovers his bicycle ruined and Miyako unconscious, the two spend their Christmas Eve together unexpectedly, and when they realize they attend the same high school, their unintentional love grows even stronger. Hiro's boyhood buddy Kei Shindou, whose pure attitude to life captures the eye of Kyosuke Tsutsumi, a womanizing photographer looking for the ideal image, is envious. Renji Asou, a lad who aspires to be a girl's knight in shining armor, meets Kei's twin sister—the exceedingly bashful Chihiro Shindou, who spends her time reading alone—at an abandoned train station.