Gen Satō Lost 15 Kilograms to Play Miyamoto Musashi
Gen Satō, the voice of Chrome in Dr. Stone and Kō Yamori in Call of the Night, leads the cast as Miyamoto Musashi. In comments released with the announcement, Satō said he traveled to Kumamoto to visit Musashi's grave, studied the swordsman's life at a local museum, and made the trip to Reigandō, the cave where Musashi wrote The Book of Five Rings. He also said he dropped roughly 15 kilograms (about 33 pounds) ahead of recording. That is not typical prep for a voice acting job, and his castmates felt the results in the booth.
Kenichirō Matsuda, who voices Thors in Vinland Saga and pulls double duty as narrator and Bond in Spy x Family, plays the famed Sengoku warrior Honda Tadakatsu. He said he treated every recording session like an actual battlefield, prepared to strain his voice to keep up with the intensity Satō brought to Musashi.
A Japan Where Nobunaga Never Fell
Tenkaichi is a martial arts period piece set in an alternate year 1600, ten years after Oda Nobunaga survived, crushed his rivals, and unified Japan. Now the aging conqueror senses death approaching, and he declares a succession plan unlike any other: the country goes to whoever backs the winner of Tenkaichi, a tournament pitting the strongest martial artists in Japan against one another. Lords across the country sponsor their own champions, which is how figures like Musashi and Tadakatsu end up trading blows for the fate of the nation. As Matsuda put it in his comment, the appeal is watching duels between historical legends that could never have happened, but that everyone has imagined.
Nobunaga himself is voiced by veteran Kenyū Horiuchi, known as Pain in Naruto: Shippuden and Kin'emon in One Piece. Horiuchi said he played the warlord so that Nobunaga's overwhelming presence cuts through his failing body, with something unsettling and half-mad underneath.
The manga, written by Yōsuke Nakamaru with art by Kyōtarō Azuma, launched in 2021 and currently runs in Kodansha's seinen magazine Monthly Young Magazine. Volume 14 hits Japanese shelves on August 20, 2026.
The Team at Studio Fugaku
According to the announcement covered by Japanese entertainment news site Comic Natalie, Masashi Abe directs the series at studio Fugaku, with Kazuharu Satō on series composition, Ryōji Nakamori on character designs, and music by Hayato Matsuo.
The teaser trailer opens with Nobunaga proclaiming the tournament, then shows the first footage of Musashi, Tadakatsu, and a lineup of other fighters. The accompanying teaser visual puts Musashi and Tadakatsu face to face, with Nobunaga looming behind them.
Looking Ahead
The anime premieres on Japanese TV in April 2027; the network and exact date have not been announced, and no international streaming partner has been confirmed yet. English readers do not have to wait to check out the source material, though. Kodansha publishes the manga in English as Tenkaichi: The Greatest Warrior Under the Rising Sun on its K MANGA app, with new chapters released simultaneously with Japan. The show's official teaser trailer is up on the anime's YouTube channel, and further casting and broadcast details are expected as the April 2027 premiere approaches.