Musashi is one of the three central characters in the anime film KILLTUBE. He was born on Sinner’s Mountain and raised by dogs until the age of five, which shaped him into a wild, fearless, and free-spirited individual. Bursting with curiosity, he lives exactly as he pleases without being tied down by anything and is described as the embodiment of freedom with no limits. After meeting the cunning yet likeable producer Kikuchiyo and the genius inventor Leonardo in a prison cell, Musashi joins the dueling video platform KILLTUBE, though somewhat under false pretenses. Initially ridiculed by audiences for his unorthodox approach, his unconventional fighting style gradually captivates the viewers and helps the trio rise in popularity. In the story, Musashi serves as the heart of the group, bringing raw instinct and an unfettered will that drives them forward in the harsh, class‑divided society of an alternate 2026 Japan still under Edo‑shogunate rule. His key relationships are with Kikuchiyo, who schemes to promote him, and Leonardo, whose inventions complement Musashi’s natural combat talent. Over the course of the film, Musashi develops from a misunderstood outsider into a celebrated fighter, though his journey ultimately forces him to confront the hidden truth behind the KILLTUBE system. His notable abilities include a fearless, instinct‑driven fighting style that breaks conventional limits, making him a force that cannot be predicted or easily contained.