Every day, Naoto Hachiouji is persistently harassed by Hayase Nagatoro, a first-year student he met at the library one day while working on his comic. After hearing his narrative and observing his uneasy manner, she chooses to play with him from then on, even calling him "Senpai" instead of his true name. Nagatoro's constant antics annoy him at first and make him feel ashamed since he is compelled to respond to her demands. However, as they spend more time together, a peculiar kind of friendship forms between them, and Naoto discovers that living with Nagatoro may even be enjoyable. But one thing is certain: his days will never be boring again.