犯下罪行的五位女子，与憎恨犯罪监狱的女教官。原本看似不相容的两方，双方竟开始互通心思，为了替狱中一位背上杀人冤罪的女囚洗清冤屈，而联手策画了一桩向某位男人的复仇计划。然而，执行计划的过程中却状况百出…… 究竟，在她们几人之中会发生什么样的羁绊和友情？

Setoka Tachibana is a female high school student who has confessed her feelings to other boys 12 times, but has been rebuffed each time. Her older brother Haruka Tachibana cares for his younger sister deeply, but he keeps secret from her that they are not blood related. One day, Setoka's first love Takane Serikawa appears after many years and approaches her.