At the end of World War II, an unknown scientist was developing a formula similar to the Super-Soldier Serum for the Empire of Japan. When the Allies came for him, the scientist drank the serum. The serum had no immediately discernible effects, as the scientist exhibited no superhuman abilities. Eventually the scientist married and had a daughter. The daughter later died in childbirth and the Japanese authorities took her son, Otomo. The Japanese government made him into a hero, and he became renowned for his proficiency against cybernetic and robot opponents.[1]

However, Otomo was dying because of his powers, so the Japanese made an antidote to save him. The Japanese controlled him with it until Shinobi Shaw synthesized the drug, bringing Otomo into his service. When Shinobi Shaw was deposed by his father Sebastian Shaw, Otomo transferred his allegiance to him.[1]

Sebastian Shaw contacted Otomo in Japan and ordered that he destroy X-51 for him. Otomo agreed, but noted that afterward, his debt would be considered paid in full.[2]

Otomo captured X-51's friend Peter Spalding so that X-51 would come to him. Jill, Peter's wife, called X-51, and he set off to rescue Peter. As Otomo waited for X-51's arrival, he narrated his origins to Spaulding, and Spaulding observed that Otomo was little more than a slave. Otomo, however, did not care, and was concerned only with destroying X-51. When X-51 arrived, he and Otomo fought, and Otomo managed to tear X-51 apart, but his nanotechnology to rebuilt him. Otomo had to admit that X-51 was superior to him, but then he began to convulse, desperately needing more of Shaw's drug. X-51 helped administer some of the synthesized drug, deciding that because of Otomo's honor he wouldn’t attack him again.[1]

Civil War

After the Civil War, instead of forcing heroes to join the Japan Defense Agency, Japan's government preferred to establish a voluntary public partnership with Big Hero Six, including Red Ronin and Otomo.[3] It was unrevealed if his powers were still active and whether or not he still required the synthetic drug to live.


Enhanced strength, durability and flight.


Skilled martial artist.


Requires drugs to stay alive.

Discover and Discuss


Like this? Let us know!

Community content is available under CC-BY-SA unless otherwise noted.

Fandom may earn an affiliate commission on sales made from links on this page.

Stream the best stories.

Fandom may earn an affiliate commission on sales made from links on this page.

Get Disney+