ちっちゃくてデカくて可愛いのに二股されてた七瀬さんを勘違い元カレから奪って幸せにする

One day during his holiday, Yuusuke Ogami happens to witness his classmate, Nanase Hiyori, confronting her childhood friend, Kouma Yoshihide.

In fact, the two had secretly been dating for a year, but during the same period, Yoshihide was also seeing another girl, essentially two-timing Hiyori.

After being hit with the lowest of words from a defiant Yoshihide, Hiyori, heartbroken, ran off. Unable to leave her like that, Yuusuke decided to chase after her to talk. This event marks the beginning of their growing connection, and Yuusuke gradually becomes closer to Hiyori.

From eating meals together at home, going on dates, to even spending the night, the mismatched couple—separated by a height difference of more than 30 centimeters—continues to close the gap between them. Meanwhile, Yoshihide, who cheated on Hiyori, still assumes that their childhood friendship gives him an advantage. Misinterpreting the situation, he smugly thinks, “Things will return to how they were soon enough,” but of course, that was never going to happen…

The main focus is on the sweet romance between the protagonist and the heroine, with a touch of comeuppance for the antagonist.