High schooler Eiyuu Sakai finds himself in an increasingly awkward situation. His two childhood friends who attend the same school, Shio Minamo and Akari Hiodoshi, have grown up to be so cute that he can no longer look at them the same way he used to. While they continue to act naturally around him, seemingly unaware of any change, Eiyuu is constantly flustered, living in fear that they might discover his new romantic feelings. He believes the resulting embarrassment would be unbearable and could potentially ruin their long friendship. What Eiyuu does not realize is that Shio and Akari might be hiding secrets of their own, as both girls may be harboring feelings for him that go beyond friendship.

The story is set in a contemporary Japanese high school and expands beyond the initial trio. As the series progresses, the romantic entanglements grow more complicated with the introduction of additional childhood friends. Runa Tsukimi, who has a younger sister-like demeanor, and Haru Hinata, a sporty and tomboyish girl, eventually enter the picture, turning what began as a love triangle into a larger romantic comedy involving four heroines. The protagonist Eiyuu (also referred to as Yonosuke in some sources) must navigate the ups and downs of high school life while dealing with the awkward events, flashbacks, and tests of friendship that arise as he sees these familiar girls in a new light.

The narrative follows a largely episodic structure, hitting many genre landmarks such as beach trips and school festivals, while slowly building the romantic tension among the group. A significant narrative arc involves the staggered introduction of the heroines; the first three are established relatively early, but the fourth love interest joins the story much later, with roughly a third of the series remaining by her arrival. The core of the series remains the central question of whether Eiyuu will ever act on his feelings or figure out which of his friends he truly likes, all while trying to prevent his relationships from becoming the awkward rom-com situation he desperately wants to avoid.