|“||The arrogance of man is thinking nature is in our control, and not the other way around.||„|
— Ishiro Serizawa (Godzilla)
Dr. Serizawa is a somewhat stoic individual with a deep respect for the organisms he studies. He very critical of the human race, particularly their attempts to dominate their planet and their scant regard for the rest of nature. He believes Godzilla's existence is in the good of nature, as he appears to restore balance when it is disrupted.
In 1999, Serizawa and his assistant Dr. Vivienne Graham are called to the Philippines to investigate a collapsed mine. There, they discover the skeleton of a long-dead member of Godzilla's species along with two giant spores, one of which is hatched.
In the fifteen years following the incident at the Janjira power plant, Serizawa, Graham and a team of Monarch scientists study the male M.U.T.O. while it is cocooned and feeding on the plant's reactor. After the M.U.T.O. breaks free from its cocoon and destroys Monarch's research facility, Serizawa and Graham are taken aboard the U.S.S. Saratoga to help the U.S. military, under the command of Admiral Willian Stenz, hunt and destroy the M.U.T.O. After discovering that Godzilla has resurfaced, Serizawa believes that he has risen to kill the M.U.T.O., which was his kind's natural enemy. Serizawa is proven correct when Godzilla swims underneath the Saratoga and confronts the M.U.T.O. in Honolulu. After Godzilla and the M.U.T.O. both leave Honolulu, Serizawa begins studying the M.U.T.O.'s echolocation patterns more carefully. Serizawa concludes that the M.U.T.O. was communicating with a female --the dormant spore-- which at this point was moved to a nuclear waste repository in Nevada. A team of soldiers is sent to the facility in Nevada and discovers that the female has hatched and is attacking Las Vegas. When the military forms a plan to lure all three monsters offshore and try to kill them with a nuclear warhead, Serizawa protests, claiming that the bomb will have no effect on the monsters and that Godzilla is only there to kill the M.U.T.O.s and restore balance. Serizawa's pleas fall on deaf ears however and the military carries out the plan, which fails after the male M.U.T.O. steals the armed warhead and delivers it to the female at their nest in the center of San Francisco. After this, Admiral Stenz agrees to Dr. Serizawa's plan to withdraw military effort to destroying the M.U.T.O. and let Godzilla handle them. After Stenz refocused military efforts to extracting the bomb, Serizawa tells an extraction team that the M.U.T.O.s have likely laid eggs underground and are keeping the warhead there.
After the battle, Serizawa and Graham gather around the seemingly dead body of Godzilla in the ruins of San Francisco. When Godzilla stirs and returns to the ocean, Serizawa looks up in joy as the monster he has dedicated so many years of his life to studying returns to his home in peace.
Ishiro Serizawa was born in 1945, before the atomic bombing of Hiroshima, to a Japanese sailor and his wife. Ishiro's father found Ishiro alone in the ruins of Hiroshima and left him with his grandparents in Kyoto for the next several years.
In 1980, Ishiro goes to visit his father in Tokyo who called him urgently. His father begins telling him things he said he would tell him when he was older: that he didn't work for a cargo company; instead he worked for a secretive government unit, and he learns about Shinomura and Gojira. Ishiro attends his father's funeral the next year in 1981 and is approached by an old Shaw. Knowing why Shaw's there, he says he's ready and joins Monarch.
- Ishiro Serizawa, at least in surname, was inspired by Daisuke Serizawa from the original 1954 Godzilla film.
- His forename is also a reference to the late legendary director Ishiro Honda.
- In issue #18 of Godzilla: Rulers of Earth a character bearing a striking resemblance to Ishiro Serizawa can be seen running from Godzilla and Ebirah, along with a character who closely resembles Vivienne Graham.