Yōsuke Nakamaru is a Japanese manga writer known for creating works in the historical action and martial arts genres. His most prominent and ongoing work is Tenkaichi: The Greatest Warrior Under the Rising Sun, a series he writes which is illustrated by artist Kyōtarō Azuma. This manga began serialization in Kodansha’s Young Magazine the 3rd in January 2021 and later transferred to Monthly Young Magazine after the former magazine ceased publication in April of that same year. The series is set in an alternate historical timeline where Oda Nobunaga successfully unified Japan and, upon his deathbed, initiates a tournament where feudal lords sponsor warriors to battle for the right to be his successor. In April 2025, an anime television series adaptation of Tenkaichi was announced, marking a significant expansion of Nakamaru’s work into animation.

Prior to Tenkaichi, Nakamaru was the creator of the manga Gamaran, which was serialized from 2009. He later continued this series with Gamaran: Shura, which began in 2018. Between these two works, he also authored Korosazaru Mono, Ikubekarazu, a manga that started in 2017. As the writer for these series, his creative identity is closely associated with action-oriented narratives often centered on martial arts conflicts and historical Japanese settings. Tenkaichi, in particular, has been noted for its portrayal of a high-stakes tournament featuring legendary historical figures such as Miyamoto Musashi and Honda Tadakatsu. The series has been published in multiple languages, including English digital releases and Spanish print editions, indicating its international reach.