Morimoto was born in Hiroshima, where he received practical training in sushi and traditional Kaiseki cuisine; he opened his own restaurant in that city in 1980.

Influenced by Western cooking styles, he decided to sell his restaurant in 1985 to travel around the United States.

He established himself in New York City and worked in some of Manhattan's prestigious restaurants, including the dining area for Sony Corporation's executive staff and visiting VIPs, the Sony Club, where he was executive chef, and at the exclusive Japanese restaurant Nobu, where he was head chef.

[11] In April 2016, Morimoto opened the restaurant Momosan Ramen & Sake on Lexington Ave. in New York City.

Notable menu items include Morimoto Fresh Tuna Pizza, Tempura Calamari Salad, Angry Lobster Pad Thai, and Ishiyaki Buri Bop, which is cooked tableside on a hot stone.

[16] Morimoto's costume on Iron Chef was silver with red trim and a picture on the back of Japanese and American flags tied together in a sheaf.

In his professional life, to distinguish himself from his on-screen persona, Morimoto wears (purely aesthetic)[citation needed] glasses.

He would usually have a bottle of Coca-Cola to drink while cooking on the show; on one occasion he combined it with nattō to fashion a dessert dish.

[17][18] Morimoto competed in the first sushi battle in Kitchen Stadium on June 18, 1999, against challenger Keiji Nakazawa.

There were five theme ingredients for the battle: tuna, eggs, Kohada (Japanese Gizzard Shad), Anago, and Kanpyō.

The Ohta faction was not happy with just one win, however, and they sent in challenger Yusuke Yamashita, a sake specialist, to battle Morimoto.

[24] When Iron Chef America was greenlighted as a regular series, it moved from Los Angeles to New York.

In the 2010 season of American version of Hell's Kitchen, Iron Chef Morimoto made an appearance on the show teaching the contestants how to make sushi.

Finalist Antonia Lofaso prepared a traditional Japanese meal for Morimoto, consisting of miso soup and a sashimi bento.

In Season 10 of MasterChef, Iron Chef Morimoto was the Guest Judge for the King of the Crabs battle.

Morimoto made a guest appearance in the 4 Million Subscriber Special of Binging with Babish, in which he prepared fugu for Andrew Rea's "death sandwich.

"[36] In November 2022, The Roku Channel ordered a cooking competition series featuring the chef, Morimoto's Sushi Master.