Yuna and Akari are two high school girls with very different views on love: Yuna dreams about romance through rose-coloured glasses, while Akari is down-to-earth and practical. Meanwhile, high school boys Kazuomi and Rio also have different views on love: Kazuomi is an airhead who can't grasp the concept of love, while Rio grabs onto any confession as an opportunity—so long as the girl looks cute. Will these four classmates end up leading a youthful romance that meets their expectations?

Centers on a boy named Osamu who receives an umbrella as a gift from Sayu, but it goes missing. That umbrella transforms into a girl who goes gallivanting around town on a rainy day.