Miya Shimada, aka Tsunami, is a superpowered character who can generate tidal waves, has superstrength, superspeed, and is an accomplished swimmer. She took a path similar to other complex characters, starting as a villain who then chose to repent and become a hero. She was created by Roy Thomas and Rick Hoberg, who introduced her in All-Star Squadron #33 (May 1984).

Miya is a Japanese-American who, like many others of her race, faced racial prejudice during World War II. Because of this, she grew bitter and decided to move to Japan where she started working for the Imperial Japanese government. Now operating as Tsunami, she returned to the US to convince other Japanese-Americans to join the cause. On this mission, she fought Liberty Belle and Starman from the All-Star Squadron and lost the battle.

Then Japan’s Prince Daka ordered her to help him steal Starman’s gravity rod. During a fight with the All-Star Squadron, Prince Daka took things too far, and Miya was horrified by his actions. The Axis powers tried to recruit her for another mission, but she didn’t want to work for them any longer. At a low point, when she was feeling lost and depressed, Miya met Neptune Perkins who convinced her to try to help her people in another way.

To help end the imprisonment of Japanese-Americans, they talked to Green Lantern and the Squadron, then they appeared to President Roosevelt. He promised to look into it, and asked Tsunami to go on a war bond tour in the meantime with other members of the All-Star Squadron. Even though she was working for the country, she was still the subject of racism during the tour. Despite that, when Axis Amerika and her former ally, Kamikaze, attacked, she went to fight them.