Atomic Samurai has long black hair tied back in a topknot. He has sunken cheeks, a defined jawline and a small goatee. His attire consists of a hooded cloak with an atom symbol on the back that’s draped over his open coat. Beneath the coat is a typical samurai gi and the footwear is a pair of waraji sandals. He sports a pair of katanas on his left hip, and based on the length, it is likely that he wields either a daito, a ōdachi, or both. The tsuka is typical for a katana, but the unique design would be the atomic shape of the guard.
Atomic Samurai has a rather prideful personality, seen when he refused to shake Saitama’s hand telling him that he only acknowledges the strong and saying that he would greet him if he makes it to the higher ranks of S-Class. He also appears to dislike being called old.