[2] When the United States entered World War II, President Franklin D. Roosevelt ordered the relocation and internment of Japanese Americans due to fears that some would turn out to be traitors.

However, for communities outside the sensitive coastal "military zone", this was not mandatory, and local authorities could not decide what they wanted to do.

Miyamura was recalled to active duty following the start of the Korean War, arriving in North Korea in November 1950.

[11] As then-brigadier general Ralph Osborne explained to Miyamura and a group of reporters upon notifying them of his medal, "If the Reds knew what he had done to a good number of their soldiers just before he was taken prisoner, they might have taken revenge on this young man.

Miyamura, a member of Company H, distinguished himself by conspicuous gallantry and intrepidity above and beyond the call of duty in action against the enemy.

Miyamura, a machinegun squad leader, aware of the imminent danger to his men unhesitatingly jumped from his shelter wielding his bayonet in close hand-to-hand combat killing approximately 10 of the enemy.

As another savage assault hit the line, he manned his machinegun and delivered withering fire until his ammunition was expended.

He maintained his magnificent stand despite his painful wounds, continuing to repel the attack until his position was overrun.

Miyamura's indomitable heroism and consummate devotion to duty reflect the utmost glory on himself and uphold the illustrious traditions on the military service.

[15] He resided in Gallup, New Mexico, after his discharge from the army, where he established a career as an automobile mechanic and service station owner.

[2] Miyamura remained active in supporting fellow veterans including work with the Wounded Warrior Project.

[17][18] In November 2022, it was announced that Miyamura joined the National Board of the State Funeral for War Veterans organization, which is dedicated to "convince Congress to pass legislation to grant a State Funeral for the last Medal of Honor recipients from the Korean and Vietnam Wars, as a final salute to all the men and women who served.