Harumi is a tutor at a private academy which aims students to get into Tokyo University. She is on the verge of getting fired. Masashi, her cousin who is in love with her appears before her and she meets Yuri, a student studying at the lowest level high school and who seems to have no interest in studying. Yuri gets inspired by Harumi and asks her to tutor him to get into university.

Harumi goes to South High as part of her teachers job to recruit more students. She meets Yamashita there, the boy she used to tutor back in school.

Harumi tries to figure out new study methods for Yuri. Harumi and Yamashita drink together. Yuri gets upset with Harumi constantly treating him like he's a kid. Harumi saves Mika from a pervert and she begins to warm up to him. Harumi helps out Masashi when he becomes sick.

Masashi confesses to Harumi but she misunderstands his confession. The cram school goes on a trip to study better. Yuri asks Harumi to remember his 18th birthday. Yuri and Harumi catch the flu.

Harumi fights for Yuri with her mother, after which Yuri comforts her. Yuri takes a mock exam, Yamashita stays over at Harumi's house after drinking and confesses to her in the morning. Yuri witnesses them being close to each other. Harumi becomes aware of Yuri's feelings.

Masashi throws a reunion party in order to get Harumi notice him. Yuri starts preparing more intensely for the Todai Entrance Exam. Yamashita confesses properly to Harumi. Harumi tries to get Yuri enrolled in Todai Cram School.

Harumi starts to feel jealous of Yuri's new teacher but then realises a true about her.

Yuri and Harumi start preparing for the last mock exam before the final exam. Yuri and Yamashita go on a date. Yuri tells Harumi about his childhood. Yuri avoids Harumi and Yamashita. Yuri's father gets tangled into a scandal and Yuri decides to stop studying. Yamashita makes a decision.

Yuri's father apologizes to him. Masashi kisses Harumi and proposes to her for marriage. Harumi tries to think more seriously of the proposal. Harumi and his friends celebrate Yuri's 18th birthday. Yuri passes the first round of Todai Entrance Exams. Harumi gets in an accident.

Masashi gets demoted when he skips his Russian conference to accompany Harumi at the hospital. Harumi rejects Masashi's proposal. Yuri gets accepted into Todai while Harumi makes a decision. Yamashita talks to Yuri. Yuri confronts Harumi.