In Gojira, Dr. Daisuke Serizawa was a young colleague of paleontologist Kyohei Yamane, betrothed to his daughter Emiko Yamane, and friend to Hideo Ogata. He saw active combat during World War II and was wounded in battle—his iconic eyepatch is worn due to wartime injuries described by Ogata only as "a terrible scar".
After the war, Dr. Serizawa, a scientist, studied elements and their effects on other objects and organisms. He eventually discovered a new element—"micro-oxygen"—that could create a destructive chemical reaction that liquefied living tissue through reaction with oxygen atoms. He was initially horrified by the destructive potential of his "Oxygen Destroyer" but chose to continue researching it, confident that he could develop it into something that would benefit society. Meanwhile, he kept its existence secret from everyone, even Emiko and Ogata.
Shortly after the first sightings of Godzilla, a journalist approached Emiko seeking an audience with Serizawa. The journalist explained that a contact in Switzerland had heard from a German scientist that Serizawa's research could hold the key to the monster's defeat, but Serizawa insisted that he had no German colleagues and apologized to the journalist, who left Serizawa and Emiko alone together.
Emiko had intended to confront her fiancé about her love for Ogata, but before she could, Serizawa decided to reveal his secret experiments to Emiko. After shocking her with the horrific effects of the Oxygen Destroyer, he swore his fiancée to secrecy, explaining that he knew that the world was not ready to know of such a terrible weapon. He remained in his lab during Godzilla's subsequent attack on Tokyo, continuing his research.
Emiko soon returned to Serizawa's lab with Ogata in tow, hoping to convince her fiancé to use the Oxygen Destroyer against Godzilla. Serizawa adamantly refused, maintaining that his weapon would only begin a new age of terror once the world saw what it could do. He scuffled briefly with Ogata in defense of his decision, but soon relented and helped Emiko as she bandaged the minor wound Ogata had received during the fight. Serizawa insisted nevertheless that he could not use the weapon even once. If his device were used to destroy the monster, he reasoned, the world would not be safe from its power as long as Serizawa was alive; his human weaknesses would be exploited by powerful people to force him to reveal the weapon's horrible secret.
Serizawa changed his mind after viewing a television report that showed the devastation Godzilla had brought upon Tokyo and the suffering of the city's people. Shaken by the utter destruction, Serizawa finally agreed to use his device, but warned Ogata that he would only use it once.
Serizawa had every intention to make certain that the secret of his ultimate weapon would remain secret. He burned all of his research concerning the device and insisted he accompany Ogata on the dive to find Godzilla and deploy the Oxygen Destroyer. When they found the monster on the seabed, Serizawa activated the device and signaled for Ogata to return to the surface, waiting until Ogata ascended before cutting his own line and dying with Godzilla. With the only prototype of the Oxygen Destroyer detonated, his notes destroyed, and his own life at an end, Dr. Serizawa hoped to ensure that no one would ever discover the same terrible power he had just unleashed. His last wish, relayed to Ogata through the diving helmet's microphone, was for Ogata, Serizawa's erstwhile romantic rival, and Emiko, now released from her engagement to Serizawa, to find happiness together.
- Godzilla Raids Again (Mentioned)
- Godzilla vs. Destoroyah (Stock Footage)
- Godzilla Against MechaGodzilla (Stock footage)
- In the American release of the film, Godzilla, King of the Monsters!, Dr. Serizawa is rewritten as being an old college friend of the main protagonist, Steve Martin (portrayed by Raymond Burr). Although no scenes were shot with them in the same room, they share a telephone conversation at one point.
- Doctor Serizawa holds the distinction of being the only human to have truly killed Godzilla, and one of very few characters to have defeated him and left him no chance to return or counter-attack.
- As testament to how memorable the character has become (a rare feat for any normal human in a Godzilla film), Serizawa is often referenced in spoofs of the kaiju genre. Most notably the anime mecha comedy series Mobile Police Patlabor, the PokéStar Studios in the fifth generation of Pokémon, and the Tokyo Grows episode of the US cartoon Pinky and the Brain. Even in Pacific Rim, Serizawa's name is used to measure the danger level of kaiju. In the 2014 American Godzilla film, one of the main characters, Ishiro Serizawa, is named after him.
- In the Godzillaencounter.com viral images, if one reads the letters in bold red and places them in order of the date when each viral image was posted, it reads SERIZAWA.