Part 4: Baki-Dou

Part 4 of the Baki series, subtitled Baki-Dou, is preceded by Baki Hanma and succeeded by BAKIDOU. The main antagonist is Musashi Miyamoto and there is no villainous faction in this part.

It continues the story of Baki Hanma, even after the defeat of his father Yujiro Hanma, he still yearns to get stronger. After becoming the strongest in the world, all Baki can do is yawn. He has become bored with life, until he hears the heartbeat of something so powerful it made him stop what he was doing. It was the heartbeat of Musashi Miyamoto, an ancient samurai brought back to life that Baki will have to battle to cure his boredom.

Also known as The Way of Baki or Baki's Path, it was written and illustrated by Keisuke Itagaki, serialized in Weekly Shounen Champion from March 20, 2014 to April 5, 2018. Collected into 22 volumes.

As of now Baki-Dou has yet to receive an official English translation.

30th Anniversary Website
''After the strongest parent-child fight in history, all the fighters were bored. At the same time, Tokugawa was planning to revive Miyamoto Musashi, a swordsman who lived in the world of warring states! The martial artists instinctively sense the birth of a new strong man and train hard for the approaching battle!''

Summary
After the conclusion of the epic battle between father and son, Baki Hanma continues to fight in the underground arena and train nonstop, but he always has to suppress his yawn caused by the overbearing boredom. No amount of stimulus or danger can bring excitement to him at this point. Now, with the inclusion of the Prime Minister of Japan in the loop, a massive cloning project is attempting to clone Musashi Miyamoto, one of the fathers of martial arts in Japan. Another fight of historical proportions awaits Baki.

Baki Gaiden: Retsu Kaiou wa Isekai Tensei Shitemo Ikkou ni Kamawan (2020 - Ongoing)
"Baki Side Story: It Doesn’t Even Matter if Kaiou Retsu is Reincarnated into Another World!" is a spinoff series, illustrated by Eiji Murai and written by Sai Ihara with the original story. It began in the November 6, 2020 issue of Monthly Shounen Champion. An isekai (fantasy in which a character is suddenly transported to another world) series depicting Kaiou Retsu reincarnated into another reality. After the events of Baki-Dou, the famous Kenpo master Retsu wakes up in a new world unknown to him and have to fight with completely new enemies.

Trivia

 * "Baki-Dou" was serialized in Weekly Shōnen Champion from March 20, 2014, to April 5, 2018. The manga consists of a total of 22 tankōbon volumes.
 * The series focuses on Baki Hanma's journey as he faces new and formidable opponents in various martial arts competitions. The narrative delves into Baki's relationships, personal growth, and the challenges he encounters on his quest to become the world's strongest martial artist.
 * "Baki-Dou" features a diverse cast of characters, including iconic figures from previous "Baki" series, new adversaries, and martial artists from around the world. The interactions and conflicts between these characters contribute to the intense and action-packed nature of the manga.
 * One prominent arc in "Baki-Dou" involves a global martial arts tournament where elite fighters from different countries showcase their skills. The tournament setting allows for a variety of unique matchups and strategic battles.
 * Similar to other entries in the "Baki" franchise, "Baki-Dou" includes cameo appearances and crossovers with characters from other works by Keisuke Itagaki. These elements add an extra layer of depth to the interconnected Baki universe.
 * Throughout "Baki-Dou," readers can observe Keisuke Itagaki's evolving art style, capturing the dynamic and powerful nature of the martial arts depicted in the series. The illustrations contribute to the visceral impact of the intense combat scenes.

Continuity

 * Since Baki and Yujiro's father and son fight in Part 3, Katsumi started special training to get better at fighting with one arm. The father-son fight also prompted many other fighters to start their training from the bottom as well, including Doppo Orocchi, and Master Motobe.
 * To cure his boredom, Hanayama asks Tokugawa if he can fight Yujiro Hanma, to rematch with him after his first fight in Part 1 at the Tokyo Game Center.
 * Since the father and son fight, Yujiro has become a celebrity and has to wear sunglasses so as not to be noticed
 * It’s been a year since Part 3
 * When Baki wonders who the heartbeat is, he wonders if it will be a man on death row or a primitive man, referencing the Most Evil Death Row Convicts Arc from Part 2 and the Pickle Wars Arc from Part 3.
 * In Chapter 41, Kaiou Retsu has a press conference about his fight with Usain Bolt, which was during the Warriors Struggle Arc in Part 3. This scene was adapted into the second season of Baki Hanma as a post-credits scene. The scene in the adaptation removed any reference to Musashi Miyamoto, though.