Ultraman Cosmos’ main form. He is a follower of peace who came from outer space, a righteous Giant with a heart of compassion as gentle as the light of the moon itself.
He came to Earth is pursuit of an Alien Baltan who was seeking to invade Earth. He runs out of energy and crash lands. His body turns transparent, and he is unable to move. With the help of a young boy Musashi Haruno, Cosmos regains his energy and entrusts a pyroxene gemstone to young Musashi, sharing his hope of stopping Alien Baltan’s plans, and then leaves Earth.
Eight years later Cosmos reappears on Earth during an invasion by Chaos Header and bonds with a now fully-grown Musashi. He takes on the Chaos Header and other dangerous foes to protect peace on Earth.
In battle, Cosmos’ fighting style embodies the essence of the Chinese martial art Tai Chi. He redirects and intercepts enemies’ attacks as much as possible, finding an opening to win by going with the flow of battle. He uses many special abilities that do not harm his opponents; Full Moon Rect quiets and calms the excitement in monsters, his Net Track Box captures opponents with a web of light, and his Luna Extract removes the violent influence of the Chaos Header from within them.