Makoto Ito rides the train to and from school every day. However, at the beginning of his second term, he falls in love with a beautiful girl that also rides the train. Unfortunately, she barely knows of his existence. Her name is Kotonoha Katsura, and though they attend the same school, they are not in the same class. In an attempt to catch her eye, Makoto enlists the aid of a close female friend of his: Sekai Saionji. She helps him, despite the fact that she—unbeknownst to Makoto—is in love with him. Thus the three are bound in a love triangle of life-changing proportions. (Source: Anime News Network)

Yuuki Ashikaga is a high school freshman in his second semester at Sakakino Academy, who from his regular visits to the school library, grows enamored by Kotonoha Katsura, a fellow classman who comes by to read. Despite already having a boyfriend, she genuinely reciprocates his interest. However things get complicated when, following a brief encounter, his sister, Chie Ashikaga, introduces him to Roka Kitsuregawa, an acquaintance who also becomes infatuated with him. Out of jealous spite for her rival, Roka attempts to dissuade Yuuki by claiming to like Makoto Itou, another schoolmate. Her lie dramatically backfires, as Yuuki, aware that Makoto is Kotonoha's boyfriend, goes to ask her about the affair.

Setsuna Kiyoura is a typical high school student enjoying the summer break off from school with her family and peers. When her close friend, Sekai Saionji, falls bedridden with a common cold and is unable to attend to her part-time waitress job at Radish, the family restaurant, Setsuna opts to fill-in until Sekai is better. Although she comes to find the job is a little more demanding and stressful than expected, she befriends a handful of acquaintances at work, becoming particularly infatuated with fellow student and patron Makoto Itou.