Oneesan-ha no Ore ga Naze Chicchai Kimi o Suki ni Natta no ka?

During the spring break following middle school, Sky Tochika steps in to rescue a petite girl from being crushed on a packed train. Assuming she is merely an elementary school student, he thinks nothing more of the encounter until his first day of high school, when he discovers her sitting right there in his classroom. Standing at just 140 centimeters tall and seemingly sustained by energy drinks, the remarkably beautiful girl introduces herself as Chito Naruse. Sky has always prided himself on being a devoted admirer of tall, older women, meaning someone as small and youthful-looking as Chito falls entirely outside his romantic preferences. However, Chito refuses to be dismissed so easily. With unwavering confidence, she launches a bold campaign to win him over, declaring her intention to completely overturn his rigid tastes. What follows is a lively romantic comedy centered on a tug-of-war between a boy who insists he only loves older women and a tiny, determined girl intent on proving him wrong.