Baki is the son of Yujiro Hanma and Emi Akezawa. Baki is also the half-brother of Jack Hanma.

The main character, and son of Yujiro Hanma. He has been training in martial arts since the age of three, and has trained under various teachers and coaches throughout his life. At the age of thirteen, he decided to take his training into his own hands and left the coaches to perform more intense training in his father's footsteps. He later meets with his father and becomes disillusioned as to his father's true character, and afterwards, aims to defeat and kill him. His fighting style is called "Total Fighting" and includes techniques from many different martial arts. He fights Arudi Regan in round 1, Zool in round 2, Igari Kanji in round 3, and Retsu Kaioh in round 4 before facing his brother in round 5 which are the finals of the tournament. He eventually develops the ogre/demon face on his back when fighting his brother, but manages to suppress it. Unlike Yujiro, he chooses to control his killing intent and fight his battles fair and honorably no matter what the outcome.Many of Baki's unusual training methods often earn him the admiration of many of the fighters of the underground arena for example Shadowboxing, or visualizing fighting an opponent, is a big part of Baki's regimen sometimes his visions take an almost corporeal form and given he can easily remember and replicate any technique he sees this gives him a huge edge over his opponents as he can fight them and learn their weakness before actually fighting them. Baki has encounters with all the escaped convicts in the "Search of Our Strongest Hero" series, has just defeated Biscuit Oliva, and is now faced with a new challenge against the prehistoric man Pickle. He is currently waiting for his fight with Pickle after Retsu and Katsumi are defeated. He had a shadow boxing visualization fight with a T-Rex prior to the Katsumi/Pickle fight. He has been recently defeated by Pickle in the Korakuen area.

During Chapter 312 of Hanma Baki, Baki makes Yujiro forfeit his title of the "Strongest Creature Alive" after making him concede in their fight