Judomaster's secret identity was Hadley "Rip" Jagger, a sergeant in World War II in the United States Army. He rescued the daughter of a Pacific island chief and in return was taught the martial art of judo.^[2] He had a kid sidekick named Tiger. In the Nightshade backup series in Captain Atom, an adult Tiger was Nightshade's martial arts instructor.

Judomaster's title lasted from #89 to #98, from June, 1966 to December 1967. It was a retitling of Gunmaster, which was itself a retitling of Six-Gun Heroes.^[3]

Along with most Charlton Comics superhero characters, the rights to Judomaster were sold to DC Comics. In post-Crisis continuity, Judomaster was said to be a member of the All-Star Squadron, DC's team of superheroes during World War II, although he has never appeared in an actual published story as a member of the team.^[4] His kid sidekick, Tiger, would later become the villain Avatar in the L.A.W. miniseries published by DC Comics, which re-teamed the Charlton characters that had been acquired by DC. In the same series it is shown Judomaster has lived for some time in the fictional city of Nanda Parbat. As time passes in a different manner there, Judomaster has retained a younger form. Since the miniseries, Judomaster has only appeared a few times.

Sometime in his life, he had a son named Thomas Jagger.

Judomaster was killed when he took part in the giant battle of Metropolis during the "Infinite Crisis" storyline during which the supervillain Bane broke his back.^[5]

Andreas Havoc, an enemy of Thunderbolt, challenged Thunderbolt to battle, feeling that his rightful position as "Vajra" had been stolen by him. The Blue Beetle, Captain Atom, and Nightshade assisted Thunderbolt in battling Havoc in a psychic battle while the new Judomaster helped rescue the heroes in the physical world. He later appeared as attending a memorial service for the citizens of Star City.^[6]

Thomas "Tommy" Jagger is the son of Hadley Jagger, from whom he inherited the name Judomaster. Jagger is also one of Checkmate's top field agents, within which he is known as the White Knight, and is an openly gay man. Jagger is conflicted when Checkmate becomes involved in the elections of Santa Prisca at the request of the United Nations. Bane, his father's killer, is suspected of ballot stuffing, intimidation, and falsifying election results. Jagger volunteers for the mission and is turned down by White King/Mr. Terrific. Josephine Tautin, the Black Queen's Knight, is picked, but a medical emergency prevents her from going. Reluctantly, Mr. Terrific agrees to Jagger's deployment, along with Fire. The mission is complicated by Fire when she acts on orders secretly given to her by Amanda Waller that results in Bane's direct intervention with Jagger. He resists the desire to avenge his father for honor, but does manage to beat Bane in a fight. The two agents make it to their exfiltration point and return to Checkmate headquarters where Jagger informs the Royals of Fire's sabotage.^[7] Jagger also spent time as an undercover Kobra devotee.

A female Judomaster, Sonia Sato, was recruited by Oracle to break into a Mexican prison. In keeping with the theme of the Birds of Prey group, this Judomaster, unlike the others, is female. Sonia's metahuman talent allows her to project an "aversion field" which prevents her from being hit by attacks specifically aimed at her. This does not include attacks that have no aim, such as random projectiles and explosions. With the help of the Justice Society of America, she stops Yakuza assassins led by Tiger. In her earlier Birds of Prey appearance, Sonia Sato is shown having an above-average mastery of English, allowing her to communicate effortlessly. During her Justice Society of America tenure, she's shown as unable to speak English, learning only with great difficulties to master a stilted, somewhat impaired command on the language.^[8] She is shown in a relationship with Damage, kissing him even after his temporarily healed face was reverted to his heavily scarred one.^[9] Sonia's romance with Damage is ended when he is killed by the reanimated Jean Loring during Blackest Night. Now part of Magog's All-Star Justice Society of America squadron, Sonia assists her teammates in repelling the Black Lantern invasion of Manhattan. Sonia and Atom Smasher search the city for survivors, only to stumble upon Damage, now a member of the Black Lantern Corps, tearing the heart out of a police officer.^[10] After the end of the Blackest Night a greatly distraught and grieving Judomaster plans to revert to her earlier plan of vengeance against Tiger, her father's killer, feeling that without Damage's love she has nothing else to anchor to a happier life. She's stopped by King Chimera, who relays her the missing half of Damage's last message to her, recorded before the Blackest Night, in which Grant shares with Sonia his wish to have corrective surgery on his face and build a simpler, happier life with her, wishing Sonia, in the event of his death, a better life. Thus King Chimera is able to convince Sonia to enact Grant's last wishes by leaving Tiger alive (albeit with a severe beating). Furthermore, Sonia decides to improve her English (reasoning that only Damage was kind enough to bear her stilted, slow grasp of language), and after giving her lover a tearful eulogy, she begins to finance several relief funds for the people Damage has unwillingly hurt in the years, attempting to give him closure, using money she "requisitioned" from Tiger before having him incarcerated.^[11] In the Watchmen sequel Doomsday Clock, Judomaster appears as a member of Japan's superhero team called Big Monster Action.^[12]