Akane, a second-year high school student, harbors romantic feelings for her younger sister, Yukari, who is a first-year. Yukari, however, finds her sister's affections to be repulsive and bothersome. The manga follows Akane's persistent pursuit of Yukari, who constantly tries to evade her. Despite Yukari's aversion, Akane's love for her sister is unwavering, even to the point of being willing to sacrifice for her. Their dynamic, often involving their amused friends, forms the basis of this high-tension sisterly gag comedy.