The legend of Hokuto returns! The year is 193X and the looming WWII is short of plunging the world into chaos. After completing the initiation ritual, the 62nd Successor of Hokuto Shinken, Kasumi Kenshiro, is called upon by the destiny of Hokuto. He embarks on a new journey to the Dutch East Indies (Indonesia) where a vicious battle unfolds over the valuable "List of Hope".

Two prisoners managed to escape after the police truck carrying them crashed on the highway. One of them , Mr Sawazaki is a gangster who has sent 10 opposite bosses to hospital. The other called "You" - our protagonist - is a con artist whose cheating profile has piled up to approximately 100 billion yen. Accidentally, "You" then becomes the new teacher for the nearby junior high school, under the new name Takeda Shindo, and according to a deal of "Hammer Session" with the headmaster. The story is about a teacher who has a past record as a con-artist. It has its own unique taste, which makes it distinctive from other series about teachers, such as GTO and Gokusen.

Six months after the events in Hammer Session!, the genius swindler Otowa Yonko returns with the goal of acquiring more formidable achievements. A chanced encounter with his former partner-in-crime Mizuki sensei however, prompts him to come to Hanazono High School to help solving his fellow students' problems, using his signature Hammer Session.