Eighteen-year-old Kunimitsu Muto arrives in New Chibagasaki City with a single-minded ambition to become a politician and reform a corrupt Japan, aiming to one day be known as the Japanese Don. His plan begins with working as a secretary for Ryoma Sakagami, a politician his late father believed was a great man who might even run the country. However, Kunimitsu finds Sakagami living in a state of disgrace, having just lost an election and now facing angry creditors at his door. The politician is cared for by his devoted secretary, Mr. Saruwatari, but receives a cold shoulder from his own children, Asuka and Shinsaku.

Kunimitsu quickly learns the city's dark reality from Asuka, who shows him an elementary school slated for demolition to make way for a new road project, a decision tainted by corrupt connections between city politicians and a construction company. When Kunimitsu seeks help from Masumi Sawa, a newly transferred reporter for the Maiasa Newspaper working out of a dilapidated branch office, she can only explain that the project has already been officially approved by the city council. A visit from council member Shunichi Fuwa, a calm and polite man who becomes visibly disturbed upon learning of Kunimitsu's connection to Sakagami, reveals the opposition Kunimitsu will face.

By a strange turn of events, Kunimitsu becomes a substitute teacher for the school's most troubled fifth-grade class, a group of students without a homeroom teacher whom other educators have abandoned. The only teacher who has tried to help them is Sayuri Yoshinaga, who warns Kunimitsu that previous teachers who opposed the school's relocation were forcibly transferred by the mayor's office. Kunimitsu rebukes her for doing nothing while her colleagues suffered, then sets out to use the classroom as his base for rallying opposition to the relocation. He proposes collecting signatures from the students, and finds a potential leader in one boy, Egashira, who commands the respect of his classmates.

The conflict escalates when Kunimitsu discovers Mayor Gokita, Fuwa, and other council members holding a lavish party at a Japanese restaurant, where the mayor threatens to expose Sakagami's attendance to undermine the opposition movement. Unable to contain his fury, Kunimitsu bursts into the room, setting the stage for a passionate battle against systemic corruption that awakens the dormant citizens of the small town. The drama unfolds across eleven episodes, following the overeager young man with strong principles and a flair for dramatic overreaction as he tackles the problems of students, parents, and politicians alike. Oshio Manabu stars as Kunimitsu Muto, with Ito Misaki as reporter Masumi Sawa, Kuranosuke Sasaki as council member Shunichi Fuwa, Miho Yoshioka as teacher Sayuri Yoshinaga, Misa Uehara as Asuka Sakagami, and Yuya Yagira as Shinsaku Sakagami.