At the close of the school year, middle schooler Yuuichi Kanba accidentally witnesses his childhood friend Makio Fujiyama, a towering 181 cm girl, in an embarrassing situation, which causes him to develop romantic feelings for her. Although Fujiyama is seen as unattractive by others, Kanba impulsively asks her out and, to his surprise, she agrees.
As they navigate school events, fireworks displays, and other activities, Kanba constantly tries to sneak glances at Fujiyama while keeping their relationship a secret from those around them. This proves challenging due to Fujiyama's imposing presence, which often draws unwanted attention.
In "Fujiyama-san wa Shishunki," Yuuichi and Makio experience a series of amusing and lighthearted moments, learning about love and each other along the way.