Suzume Yosano (Mei Nagano) is a first grade high school student. She lived in the countryside, but, due to her parents transferring overseas for work, Suzume now lives in Tokyo with her uncle (Ryuta Sato). Suzume has never had a boyfriend before, but she has feelings for her homeroom teacher Satsuki Shishio (Shohei Miura). Meanwhile, her classmate, Daiki Mamura (Aran Shirahama), becomes attracted to Suzume.
Isao Komori is a college dropout who spends his days cooped up in his apartment playing video games. The highlight of his day is visiting a convenience store where an angel-like high-school girl called Mari visits every night.
One morning Komori wakes up in Mari's body. Another "Komori" inhabits his old body, and Mari has disappeared. Komori struggles to maintain Mari's ordinary life and starts to investigate Mari's disappearance.
So Utsumi (Mahiro Takasugi) doesn't have many friend. After school and before going to a private institute, he kills time by doing nothing on the riverside. One day, Shokichi Seto (Shono Hayama) appears in front of him. Shokichi quit the soccer team and he nothing to do. They spend time together.
In front of the two guys, Ichigo Kashimura and Hatsumi, from the same high school, appears.
Hina has repeatedly transferred schools due to her father's job and has always dreamed of a normal high-school life. At her new school, however, she finds that her class is comprised solely of guys! On top of that, five mischievous boys from her class have taken a liking to her...!?
Kahoko Nemoto (Mitsuki Takahata) is a naive 21-year-old university student. She relies on her mother, Izumi (Hitomi Kuroki), for everything in her life. Her mother wakes her up everyday, picks up her clothes, while Kahoko Nemoto has never done housework or driven a car. One day, Kahoko Nemoto meets a young man who grew up in a completely opposite environment.
Arata Kaizaki (Taishi Nakagawa) is 27-years-old and unemployed. He quit his prior job after working for the company for 3 months. Arata Kaizaki decides to take part in a research program "ReLIFE." He takes medication that makes him look 10 years younger and he is to attend high school for a year. There, he falls in love with female high school student Chizuru Hishiro (Yuna Taira).
In the town of Sakurada, where about half of the residents have special abilities, Kei Asai (Shuhei Nomura) is a high school student and is able to remember everything. Misora Haruki (Yuina Kuroshima) is also a high school student and she has the power to reset the world by 3 days. If they use both of their powers together, they can go back in time by 3 days and retain their memory. They are watched by the administrative bureau.
Hikari Tomonaga (Suzu Hirose) joins the cheerdance club at Fukui Chuo High School. She joins the club to impress Kosuke Yamashita (Mackenyu), whom she has known since junior high. The club itself was recently converted from a baton twirling club.
At the cheerdance club, Hikari Tomonaga meets Ayano Tamaki (Ayami Nakajo), Yui Kito (Hirona Yamazaki) and others. The girls enjoy dancing together as a unit, but they must endure their ultra-strict instructor Kaoruko Saotome (Yuki Amami) and her rules. Kaoruko Saotome announces that they will compete at the USA Cheerdance Championship.
Kako Motoya (Tao Tsuchiya) is in the first year of high school. She has yet to have a boyfriend yet. One day, she pretends she's a university student and takes part in a group blind date. There, she meets 23-years-old Kota Sagano (Kazuya Kamenashi). Kako and Kota get along well and become attracted to each other. Later, Kota learns that Kako is a high school student and his attitude towards Kako changes. In fact, Kota is police officer. Even though he likes her, he knows he can't date her. Then, Kako is injured while protecting Kota. Kota decides to accept Kako for who she is. He asks Kako to marry him, because that's the only way he can be with her as a police officer.
Haruta (Shori Sato) is handsome and smart, Chika (Kanna Hashimoto) is bright and naive. When they were children, they were friends until Haruta’s family moved away while he was in the 3rd grade. They meet again during a high school entrance ceremony. After all of these years, Chika is eager to join the wind instrument club. Due to an incident, the wind instrument club is about to be disbanded. Chika can't give up the flute so she attracts Haruta to her side and tries to recruit members from the wind instrument club. The group attempts to solve various cases taking place at their school while they plan to take part in a contest.