Baki Rahen is the sixth part in the Baki franchise, which usually centers around the titular character's quest to defeat his father, Yuujirou Hanma. However, Baki isn't the only person in the world with the goal of beating Yuujirou. His half-brother Jack Hanma is in a similar position, and during Baki's adventures, Jack has been steadily getting stronger in the background. This time the series focuses on Jack's own path in life and his constant struggle to gain more and more strength.

The prodigy son of the monstrous Yujiro Hanma, has trained his entire life to surpass his father.  Driven by an insatiable hunger for strength, Baki has honed his martial arts skills to an incredible degree.  Baki-Dou (Baki the Grappler) Gaiden: Ragnarok - Baki Hanma ventures beyond the previous series, delving deeper into Baki's motivations and the formidable opponents he encounters on his journey.