Toru and Run have been best friends forever, so when Toru learns that she’s been accepted to the same high school as Run, she runs to tell her… only to find Run in a compromising position with another girl, Yuko. Needless to say, that makes things a bit awkward at school, with Toru fending off those who might be interested in Run while Yuko and their other girlfriend, Nagi, have to deal with Run’s own penchant for drama. When it comes to learning about the real world, there’s always something ‘educational’ to be found in A-CHANNEL!
Toru is overjoyed when she is accepted to the same high school her best friend, Run, attends. But when she meets, Yuko, a new friend of Run's, she is immediately threatened and feels her friendship with Run is at risk.
Due to sleep deprivation, Run collapses—but not before leaving the house without any panties on. After a downpour, Yuko and Run stay at Nagi’s to dry off where they have a bath and suffer through a scary movie.
Mr. Sato is (strangely) attracted to Run’s forehead. A classmate named Yutaka becomes overly fond of Tooru, which sparks feelings of jealousy in Run.
Nagi worries that she is gaining weight and subsequently begins to diet. The newly formed bond between Miho and Tooru proves to be a source of chagrin for Yutaka.
Run suggests that everyone go to the beach. Nagi and Yuko shop for new swim suits. Later, they enjoy fun in the sun.
Tooru finds it difficult to deal with her teachers. Run gives Tooru a bad haircut, and Mr. Sato collapses.
Tooru and Run sing a duet at a karaoke bar. From the next room, they hear a beautiful voice which belongs to someone they know.
Summer vacation comes to a reluctant end. As classes resume, Tooru and Run have a disagreement. Yutaka is still unusually attached to Tooru.
The girls plan a party for which Run and Yuko attempt to prepare food. Tooru and Nagi, on an excursion to buy snacks for the party, find a dirty magazine in which the main character looks uncannily similar to Yuko.
Tooru takes in a stray kitten. Winter arrives and snow falls. All the students have fun in the snow, but they pay for it the next day by catching colds.
Run recalls two years prior when Tooru helped her study for her entrance exams. Tooru’s birthday approaches, and Run makes her a cake.
Tooru worries about what life will be like after everyone graduates. Yutaka rescues a cat in a tree, and Tooru finds peace with the upcoming changes.