Izumi Yasunari is a Japanese solar physicist who is a longtime member of the Global Guardians. His grandparents were survivors of the atom bomb dropped on Nagasaki, Japan, by the U.S. in 1945, which brought World War II to an end. Both of them later developed cancer and died. The same happened to Yasunari's mother also developed cancer but recovered with chemotherapy. A horrified Yasunari and his brother, Wataru became doctors specializing in cancer research. Their troubled sister, Kaori, joined a religious cult. Rising Sun is a founding member of the Japanese equivalent of the Justice League of America, a team called Big Science Action which came together to defend the hero Ultimon from the Monster Army.
His first known mission was helping Atom dismantle a bomb in Japan. He later helped Robin defeat a villain. Spurred on by Doctor Mist, he helped Superman find a piece of ancient armor and soon after, he and his Guardians assisted Superman in a battles against ancient sorcerers who were casting a spell amid the Moai (Statues) of Easter Island. He helps save Japan in the Crisis on Infinite Earths, and helps Artemis save her parents, Huntress and Sportsmaster with the help of Infinity Inc.. The Japanese hero volunteers to help the Queen Bee but was brainwashed by her forces and technology. Under her influence he destroyed a Neo-Nazi stronghold in Germany, killing many of the people inside. When Justice League members Power Girl and Rocket Red arrive, he attacked them also, believing them to be Nazi loyalists. When defeated, he fell into a coma, all part of a plan.
While in a coma, he was taken care of at the Justice League International embassy in Tokyo, Japan. He awoke at the call of the Queen Bee, at the same time as his friends Wild Huntsman and Tuatara, who were also in comas. These two had also attacked Nazi facilities and had fallen into comas when defeated by Justice League members.
All three returned to duty with the Global Guardians, where they were duly brainwashed. After a few battles with his team, Izumi secretly betrays them and helps fellow Japanese hero Doctor Light battle a horde of Bialyan soldiers. Afterwards, he joins with Doctor Mist, Jack O'Lantern, and Owlwoman together and he helps the three heroes reform the Global Guardians.
Fain Y'onia, an ancient enemy of Doctor Mist, targeted the team. Impala and Godiva were rendered powerless. Bushmaster was killed. The Guardians rallied and ambushed Fain in the Arizona desert. This did not go well. Tuatara was badly injured and Thunderlord was killed. The Wild Huntsman went M.I.A., taking Fain with him. Working with the other Guardians still mobile, and with the assistance of the Martian Manhunter, Rising Sun helped reform the team. He has courted the female Doctor Light, sometimes to the point of angering her.
He next appeared during Infinite Crisis. He and Doctor Light were attempting to protect the people of Tokyo from various natural disasters. Just before the Final Crisis, Rising Sun was interviewed for a retrospective on Big Science Action and their battle with Fushikuraje, an ancient kaiju who had demolished much of Tokyo in an attempt to reach the monster graveyard below Mount Fuji. On the program Rising Sun derided the new younger generation of Japanese heroes, and their obsession with fame, claiming that they dishonored Japan's tradition of superheroing and monster-battling.
Since the Final Crisis, Rising Sun has not been well. He gatecrashed a party held by the Super Young Team's, was barred from entering Tokyo by the Japanese SDF, and was apparently possessed by a worm in a bottle of tequila. Since then, he killed the staff of Innovative Concepts, Inc., the the company who markets Super Young Team. and went to confront Super Young Team in the ruins of Midway City (which had been damaged during Final Crisis). The team had trouble with his heightened powers, but discovered he was being controlled by the supervillain Mister Mind who had taken residence inside his brain, and with Mister Mind's defeat Rising Sun was freed of his control.
- Energy Absorption: Rising Sun has the ability to absorb and channel ultraviolet radiation.
- Energy Projection: Rising Sun can harness the energy that he absorbs and release as concentrated blasts of solar energy or streams of flame from his hands. Rising Sun's energy projection is a form of Pyrokinesis.
- Flight: Rising Sun can fly under his own willpower. His velocity and rate of climb while flying is unknown.
- Rising Sun first appeared in Super Friends continuity in Super Friends #8 by E. Nelson Bridwell and Ramona Fradon. He was introduced in mainstream continuity in DC Comics Presents #46 by E. Nelson Bridwell and Alex Saviuk.
- 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. (Technically the Earth-One Isuma Yasunari died in Crisis on Infinite Earths.)
- 39 Appearances of Isuma Yasunari (New Earth)
- 3 Images featuring Isuma Yasunari (New Earth)
- Quotations by or about Isuma Yasunari (New Earth)
- Character Gallery: Isuma Yasunari (New Earth)