Kenichi Shirahama has grown far beyond the bullied high school student he once was. After years of grueling training under the masters of Ryōzanpaku, he has defeated the gangs of Ragnarok and survived the deadly conspiracy of Yami. Now, the sequel manga picks up his journey as he and his friends enter a new chapter of their lives. The story resumes with Kenichi continuing his relentless pursuit of martial arts mastery, living and training alongside the woman he loves, Miu Fūrinji, and the six eccentric masters who have become his family.

The setting remains rooted in the world of Ryōzanpaku, a dojo that serves as a sanctuary for martial artists who follow the way of Katsujin-ken, the life-giving sword. However, the narrative scope is expanding. While the original series followed Kenichi's climb from weakness to strength, this new arc, subtitled Tatsujin-hen or Masters Arc, focuses on his transition into a true expert, or Tatsujin. The peaceful days of training are short-lived, as new battles are already on the horizon, forcing Kenichi to test everything he has learned against threats that may require him to finally bridge the gap between disciple and master.

Familiar faces return to center stage. Kenichi Shirahama is no longer the timid novice but a confident and powerful martial artist, though he still lacks killer intent and holds tightly to his moral code. He is joined by Miu Fūrinji, his classmate, love interest, and the granddaughter of the invincible super master Hayato Fūrinji. The terrifying yet loving masters of Ryōzanpaku are all present: Shio Sakaki the karate master, Apachai Hopachai the Muay Thai fighter, Shigure Kōsaka the weapons mistress, Akisame Kōetsuji the jujitsu philosopher, and Kensei Ma the Chinese Kenpō master. The scheming tactician Haruo Niijima also returns, likely bringing his unique brand of manipulation and strategy to support the team.

As the sequel begins, the story directly follows the conclusion of the original manga. Kenichi and Miu are shown continuing their rigorous training routines, suggesting that while the great war against Yami is over, the quest for self-improvement never ends. The narrative is poised to explore a more mature stage of Kenichi's life, moving away from basic survival and toward the absolute pinnacle of combat. With the subtitle Masters Arc, the plot is expected to delve deeper into the legacy of the martial arts, potentially introducing a new generation of rivals or remnants of old organizations who seek to challenge the peace Kenichi helped secure. The ultimate goal remains clear: Kenichi must one day fulfill the vow to defeat Hayato Fūrinji if he ever wishes to marry Miu, a task that seems impossible but now, perhaps, slightly less so.