Mihane Yoshiyama (Yuina Kuroshima) is a 3rd grade high school student. She is a member of the photo club at her school. The day before her summer vacation, she smells a lavender scent in the science lab and she suddenly gains the ability to leap through time. Shohei Fukamachi (Fuma Kikuchi) is Mihane’s classmate. He actually came from the year 2122 and is a researcher. Shohei lost a drug that allows him to go back to 2122. In the meantime, Shohei hypnotizes those around him and lives as a high school student.
Mihane and Shohei become to have feelings for each other.
Tooru Igarashi (Kotaro Koizumi) is a lecturer with charisma, working at a prestigious preparatory school. Recently, he drinks a lot and his life falls apart. Maki Endo (Haruna Kawaguchi) is a student at a part-time high school. Every day, she is exhausted with working multiple jobs to cover her expenses. One day, Tooru and Maki happen to meet each other. Maki wants to graduate high school to get a regular job and asks Tooru to tutor her for her test–retest. After Tooru quit his prep school job, he has lost his pride and passion to teach. Tooru was also diagnosed to have only a year left to live. He decides to teach Maki and get her into the University of Tokyo.
Koichi Hikuma (Akira Terao) was a saxophone player, but he suffers from the aftereffects of an accident. Due to that, he turned his back on music. Koichi Hikuma finds hope in the high school brand band. The band consists of problem students. Koichi struggles to instruct the brass band and to give them hope.
Yuiko Yoshioka (Mei Nagano) begins the first grade in high school. She gets sick with the cold and stays in bed. At that time, she gets a phone call from class president Matsubara. Yuiko becomes fluttered by his kind voice on the phone. The next day, she goes to school and meets Matsubara. He is a mysterious boy, wearing a paper bag over his head. Her high school days begin with pounding heart.