The story chronicles the school years of Junpei Manaka, a student, aspiring movie director, and his relationships with the girls that enter his life. In the beginning, he encounters a mysterious and beautiful girl on the roof of his middle school and only remembers that she had strawberry-pattern panties. She leaves before he can talk to her but he finds a notebook nearby, belonging to Aya Toujou (an ordinary-looking glasses-wearing girl who is a gifted writer). The two become friends with the common ambition of turning great stories into movies. Thinking that Tsukasa Nishino (the most popular girl in his school) might be the mystery girl, he asked her out while doing a pull-up at the chin-up bar and was surprised when she accepted. He later realizes Tsukasa is not the mystery girl but continues dating her anyway. He places into Izumizaka High, but learns that Aya has given up an offer to the prestigious Oumi Academy to attend Izumizaka with him and that she is the mystery girl.

At Izumizaka, Junpei encounters a feisty girl named Satsuki Kitaoji. The two become friends because of common interests, but Satsuki falls in love with him. Junpei tries to join the film club but learns it has been disbanded. He revives the club thanks to Aya, Satsuki, and his high school friends as members. Junpei also discovers that his childhood friend Yui Minamito is moving into his family's home, but she ends up attending Oumi Academy. The film club produces one film per year, each written by Aya and directed by Junpei, which is screened at the school festival. Satsuki stars in their first film, Tsukasa is the heroine of their second film, and Aya is the heroine of the third movie.

Over the course of his high school life, Junpei experiences many awkward sexual and romantic moments involving the four girls in his life. Even though he is seeing Tsukasa, he also has feelings for Aya and remains indecisive about whom he really loves. Aware of the situation, Tsukasa grows impatient and breaks up with him. During this time, Junpei and Aya's mutual feelings start to grow; when Junpei finds out that Tsukasa still thinks about him, he becomes indecisive again. Things got more complicated as the students enter their third year and face college education and career choices. Tsukasa plans to become a patissier in Paris and Aya decides to go to the same college Junpei has chosen. She even goes to the same cram school as him even though their friends disagree with her decision to give up better schools just to help Junpei make films. Aya eventually tells Junpei she also wishes to try for the university her parents recommended, much to Junpei's disappointment.

Matters come to a head when Junpei sees Aya with her brother and mistakes him for a new boyfriend. Having attended the same high school and made films together, he thought that Aya will always be with him and is unable to accept her supposed new relationship. When Tsukasa confesses that she wants to be Junpei's girlfriend again, he seeks comfort from her, but later denies that it was because of Aya. He later finds out the truth and that Aya has always been in love with him, but Junpei does not want to be unfair to Tsukasa and stays with her. Later, even at the risk of Tsukasa finding someone else, Junpei decides to break up with her. Junpei feels that he has not matured enough to be with Tsukasa and needs to continue developing as both a film-maker and as a person. After graduation, the friends part company, each of them chasing after their own goals and ambitions.

Four years later, Satsuki has become the owner of a relative's restaurant and the gang chooses her restaurant as the spot for their reunion. Aya attended the prestigious university her academic achievements warranted and has become a successful writer and a more assertive person, even winning the Naoki prize (the Japanese equivalent of the Pulitzer prize). Junpei has won an award and has been accepted into a film studio after years of personal development. He is able to congratulate Aya on her accomplishments without jealousy now and hopes to adapt her notebook novel into film. In the end, Junpei reunites with Tsukasa, who has returned after several years in Paris, and the two rekindle their relationship.