Falling in love with a clueless boy would turn any girl into a cactus!

Miku Yamada has a longtime crush on classmate Kyohei Fujioka. But no matter how many times she tries to show him how she feels, clueless Kyohei just doesn't get it. Frustrated, Miku gives up on him, only to have him start calling her "Cactus" for being prickly when he's around. Will Kyohei ever figure out Cactus's secret?

Miku and Kyohei are dating now, but soon they must make decisions about their future after high school. But just when Miku starts to make plans for attending university, it seems Kyohei wants to break up.