A massive prehistoric African elephant goes on a rampage, making headlines around the world. The sole survivor of this attack claims the beast was killed by a single, unarmed person, unknowingly referring to Yuujirou Hanma, known as "the Ogre" and sometimes called "Earth's strongest being." At the same time, Yuujirou's 18-year-old son, Baki, undergoes intense training against a formidable praying mantis.
Feeling prepared and driven to surpass his father, Baki kidnaps U.S. President George Bosch to set his plan in motion, leading to his deliberate imprisonment in the notorious Arizona State Prison. There, Baki encounters Oliva Biscuit, the most powerful prisoner in the country, who is free to leave whenever he wants. Eager to test his strength, Baki challenges Oliva. However, Oliva is busy with his strange opponent, Jun Guevaru, also called "the Second," the only other inmate granted special privileges.
Perplexed but curious, Baki learns about his fellow prisoners and endures the harsh conditions of prison life while waiting for the right moment.