The sequel series Cobra Kai (2018–2025), produced after Morita's death in 2005, frequently references Miyagi through dialogue and archival images and follows Daniel as he reopens Miyagi-Do as its sensei to continue his mentor's teachings.

The character originated in a screenplay written for The Karate Kid by American screenwriter Robert Mark Kamen.

[2] The original preferred choice for the role was Toshiro Mifune, who had appeared in the Akira Kurosawa films Rashomon (1950), Seven Samurai (1954), and The Hidden Fortress (1958), but the actor did not speak English.

Pat Morita later auditioned for the role, but was initially rejected for the part due to his close association with stand-up comedy, and with the character Arnold from Happy Days.

[3] Morita eventually tested five times before Weintraub himself offered him the role,[3] ultimately winning it because he grew a beard and patterned his accent after his uncle.

[9] The Karate Kid provides insight into the character's difficult past during a scene where he drunkenly shows Daniel a photograph of his wife, who died in childbirth along with his son.

Born on June 9, 1925, Mr. Miyagi left Okinawa at the age of 18 and emigrated to the United States after defying convention and unsuccessfully declaring his love for Yukie, a girl intended to marry his best friend Sato.

At the onset of World War II, Miyagi and his wife move to Manzanar, a Japanese-American internment camp in California.

During this time, he serves overseas in the 442nd Regimental Combat Team in the United States army, for which he receives the highest military award, a Medal of Honor, but loses his wife and son in childbirth.

[1] Miyagi is working as a maintenance man at the South Seas apartment complex when Daniel LaRusso and his mother moved in.

When Daniel throws away his bike after it is damaged in an ambush by Johnny Lawrence and other members of Cobra Kai, Miyagi repairs and returns it.

A meeting with John Kreese – a former Special Forces veteran running the Cobra Kai dojo and the bullies' sensei – proves largely futile.

Kreese consents to a cessation of hostilities until the time of The All-Valley Karate tournament, where Daniel and the Cobra Kai students will compete.

One night, Daniel finds Miyagi drunkenly lamenting the death of his wife and newborn son during childbirth at Manzanar while he was serving in Europe during World War II.

John Kreese is attempting to resurrect Cobra Kai and get revenge on Daniel and Miyagi with the help of his friend Terry Silver, who hires Mike Barnes, a vicious karate expert.

Daniel and his new neighbor, Jessica Andrews, decide to sell a valuable bonsai tree that Miyagi had brought back from Okinawa.

He performs triage on the bonsai while confessing that he sold his truck to obtain a new stock of trees and that he cannot train Daniel for the tournament.

Miyagi travels to Arlington National Cemetery for a commendation for Japanese-Americans who fought in the 442nd Regimental Combat Team during World War II.

Julie's issues cause friction at school and with Miyagi; he watches as she attempts to leave and narrowly misses being struck by a car by managing to jump into a tiger crouch onto the hood.

There, he teaches Julie the true ways of karate – balance, coordination, awareness, and respect for all life – and helps her overcome her anger issues.

Things go awry when Julie and her date, Eric McGowen, come under siege by Colonel Dugan and the Alpha Elite.

[12] In Part 1, Cobra Kai season 6, Daniel, Chozen, and Amanda learn that Mr. Miyagi had a secret past when they find a hidden box in his house.

[13] Amanda discovers a news clipping dated May 3, 1947, that details the beating and assault of Jim Watkins, who was from Lodi.

[14] In Part 2 of Cobra Kai season 6, Daniel uncovers a Sekai Taikai record which reveals Miyagi's fight in the competition against "Claramunt" ended in death.

[16][17] In 1989, Mr. Miyagi appeared alongside Daniel LaRusso in The Karate Kid animated television series, voiced by Robert Ito.

[23][24] [25] Although Morita died in 2005, Macchio wrote in an imaginary 2022 letter to him that due to the Cobra Kai series, the "legacy of your work and contribution to the world in your portrayal of Mr. Miyagi shines brighter than ever.