Sonny Sumo was an honor-bound warrior who held fast to old Japanese traditions. Proficient in the competitive sport of Sumo, Sonny was forced to use his skills for money in underworld competition. Sonny's rivals were not always traditional sportsman however. In one event, Sonny's manager Harry Sharp set him up against a robot warrior named Sagutai. Sagutai greatly wounded Sonny Sumo, but the trained athlete was able to call upon his inner chi to heal his wounds. Sonny Sumo also possessed an aspect of the Anti-Life Equation. He first discovered that he held this key to ultimate power when he encountered a team of adventureres known as the Forever People. The Forever People used their Mother Box to unlock the Anti-Life Equation inside of Sonny. Shortly thereafter, the evil scientist DeSaad captured the Forever People and imprisoned them inside of his twisted amusement park, Happyland. Sonny went to Happyland and helped free the Forever People. Unlocking the power of the Anti-Life Equation, he was able to use it to incapacitate Darkseid's troops by ordering them to "Sleep". Enraged by his minion's defeat, Darkseid used the Omega Effect to send Sonny and the Forever People into different points in the time stream. Little is known of Sonny's exploits after this, nor is it known exactly what point of the timeline he ended up in. Wherever he arrived though, he knew that he still needed to help out the Forever People, so he planted the Mother Box in a place where he knew his friends would one day find it. Whatever became of Sonny Sumo since then is unknown.
Years later, during the events of the Final Crisis, Sonny Sumo was met by Shilo Norman at a metahuman nightclub in Tokyo, mere minutes after Sonny had been forced to kill a drunken cyborg named Megayakuza. Explaining that Darkseid and his Fourth World minions were now active on Earth, he recruited Sonny Sumo and the Super Young Team (who had been trying to get Sonny's autograph) to help him fight them.
- Although this character was originally introduced during DC's Earth-One era of publication, their existence following the events of the 1985–86 limited series Crisis on Infinite Earths remains intact. However, some elements of the character's Pre-Crisis history may have been altered or removed for Post-Crisis New Earth continuity, and should be considered apocryphal.
- 10 Appearances of Sonny Sumo (New Earth)
- 1 Images featuring Sonny Sumo (New Earth)
- 1 Quotations by or about Sonny Sumo (New Earth)
- Character Gallery: Sonny Sumo (New Earth)