After 18 years of fighting and pushing his body beyond its natural limits, Baki Hanma is almost ready to face his father Yuujirou in one final battle. Publicly challenging his father to a revenge bout for the title of "World's Strongest," Baki sets out to train himself even further. He targets the few men who are said to hold comparable power to Yuujirou, including the "Unchained" bounty hunter Biscuit Olivia and a prehistoric human named Pickle revived from the Mesozoic era.

The demonic Yuujirou monitors his son's training with a growing anticipation. The "Ogre" sees Baki as little more than a savory meal marinating for him to devour. Still, Yuujirou exists in solitude at the top of the mountain of strength. He yearns for a combatant to rise up and prove themselves a worthy opponent capable of giving him a challenge. Despite viewing his son as pathetic, Yuujirou can't help but hope his child will be the one to give him the thrill of equal combat he has lived so long without.

As Baki seeks to understand his father's monstrous legacy, Yuujirou comes to terms with his true feelings toward his son. The two Hanmas advance toward their climactic fight to decide who is really the "World's Strongest."