Makio Sakaki (Tomoya Nagase) is the son of the boss of the Kanto underworld Sharp Teeth Club. He shoulders the important mission of inheriting the club. However, because he "can only think about things for the first 90 seconds", he will use violence to solve problems when he fails to reach an agreement. He has ruined several deals and caused heavy losses to the organization. The worried father decided to send Makio to high school for a year of re-education. Although his worried younger brother Kazuya (Tanaka Sei) secretly came to "protect" him, Makio still made a series of jokes in school and was ridiculed for not keeping up with his studies. Fortunately, with the encouragement of the enthusiastic and friendly Sakurakoji (Tegoshi Yuya) and Hikari (Aragaki Yui), Makio regained his confidence and first became a class leader. After winning the ball skills competition, he began to gradually gain recognition, and the road to becoming the boss was very good!