As far as it goes, many boys, especially in their teenage years, want to have a girlfriend. Keiki Kiryuu is no exception. One eventful afternoon, his days of yearning for a lover seem to come to an end when he receives a love letter from an anonymous sender—along with a pair of white panties. To determine the identity of his secret admirer, referred to as Cinderella, he proceeds to investigate several possible candidates including his senior Sayuki Tokihara, his underclassman Yuika Koga, and his classmate Mao Nanjou. However, as Keiki seeks to uncover who this mystery girl might be, he comes to know about the perverted fetishes hidden behind each candidate's innocent exteriors...

As another school year begins drawing to a close, the third-year high school students move steadily toward the next milestone of their lives: graduation. Among them are Mio Natsume, a girl burdened with lingering feelings; Hazuki Morikawa, a member of the concert band but distant from the others; and Haruto Souma, an athlete obsessed with baseball. Meanwhile, second-year student Ena Komiya seeks to revive the photography club to its former glory, refusing to let the organization be disbanded. Though this group lacks a strong connection with one another, their lives suddenly cross paths with the arrival of a third-year transfer student. While a transfer so close to graduation is unusual for most, it is business as usual for Eita Izumi. Due to his father's work, he has never been able to stay in one place for very long. But as luck would have it, their most recent relocation has returned Eita to his hometown for his final semester of high school. For better or worse, it also sparks the rekindling of old relationships left behind in the past. With graduation already causing its own share of anxieties, Eita's sudden arrival brings these students' carefree days to an abrupt end. Long-forgotten memories, deeply buried emotions, and inspiring new passions—everything is brought to light in their bittersweet final semester.

Kimihiko Kimizuka has found himself inadvertently entangled in various crimes more times than he can remember, referring to himself as a magnet for trouble. One day, as if it was nothing out of the ordinary, a group of unknown men kidnaps him, forcing him to board a flight—where he also encounters a hijacking. Amid the resulting chaos, however, Kimizuka meets a stunning silver-haired beauty, going by the codename Siesta, who then saves the day. Claiming to be a legendary detective, Siesta enlists Kimizuka to be her sidekick. Though Kimizuka refuses at first, with Siesta's insistence, he eventually joins her—marking the start of a grand adventure spanning the entire world, preventing multiple threats that could spell doom for humanity along the way. Unfortunately, after three years of their unpredictable yet enjoyable time together, Siesta abruptly passes away. Distraught, Kimizuka tries to leave all memories of her behind, but as he begins to meet more people, it seems that Siesta's influence will never truly die.

Miou Aida and Haruki Serizawa might seem like polar opposites to those around them, but as the two third-years prepare to end their high school experience, they couldn't have been closer. While Miou is a shy and reserved member of the school art club that prefers to stay out of the limelight, Haruki is the boisterous and confident ace of the movie club, already winning awards for his directing prowess. However, after a previous chance encounter during their school entrance ceremony, they quickly become friends despite their stark differences in personality. But although their closeness might be growing, they've never become anything more than just that, much to the bewilderment of their friends. As their time in high school draws to a close, Miou and Haruki, along with their friends in the art and movie clubs, have just one year left to face their hidden feelings and the daunting task of deciding their future careers. The two might always be only an arm's reach away, but as Haruki chases his dream of becoming a professional movie director and Miou struggles with choosing a path for herself, they'll learn just how hard it is to get past those last 10 centimeters.