Yuuki Ashikaga is a high school freshman in his second semester at Sakakino Academy. Through his regular visits to the school library, he becomes enamored with Kotonoha Katsura, a classmate who comes by to read. Because of Kotonoha's friendly demeanor, Yuuki convinces himself that she reciprocates his feelings. However, things become complicated when, after a brief encounter, his sister, Chie Ashikaga, introduces him to Roka Kitsuregawa, an acquaintance who also becomes infatuated with him. Out of jealous spite toward her rival, Roka tries to dissuade Yuuki by claiming she likes Makoto Itou, another schoolmate. Her lie backfires dramatically, as Yuuki, knowing that Makoto is Kotonoha's boyfriend, goes to ask her about the situation.