About to start her first year of high school, Sakurako Kawawa settles into her new lodgings. But when she meets her new roommate—the beautiful Kasumi Yamabuki—everything changes! From day one the responsible, level-headed Sakurako and lazy, easygoing Kasumi find themselves at odds with one another, but with their matching mugs and one bed to share, Sakurako and Kasumi's friendship is just beginning!