A 12-year-old girl and boy share a diary and call themselves boyfriend and girlfriend, and the show treats it with complete sincerity. There's no winking at the camera, no joke about how innocent childhood romance is. It just lets them exist in that small, genuine feeling of being chosen by someone who matters. The entire series is built on the quiet magic of being liked for who you actually are, even when you hate your own nickname.

Azusa Noyama is a twelve-year-old fifth grader whom everyone calls Azuki-chan, a name meaning red bean that stuck after she was misnamed back in first grade. She has never much liked it. Then a transfer student, Yuunosuke Ogasawara, joins her class. When a boy named Ken-chan teases her about the nickname, Yuunosuke happens by, and she becomes the first girl in class whose name he remembers. He asks about her nickname and says he likes it. Azuki falls for him, suddenly decides her unusual nickname is a nice thing to have, and the two begin going out, sharing a diary as boyfriend and girlfriend. The result is a long-running romantic comedy set in everyday school life.