Hammer Session!

Two prisoners managed to escape after the police truck carrying them crashed on the highway. One of them, Imamura Shouhei is a gangster who has sent 10 opposite bosses to hospital. The other called Yazwa Yuu—our protagonist—is a con artist whose cheating profile has piled up to approximately 100 billion yen. Accidentally, Yuu then becomes the new teacher for the nearby junior high school, under the new name Hachisuka Gorou, and according to a deal of "Hammer Session" with the headmaster.

(Source: MU)