Jun Oki

Ultraman Leo is an Ultra foreign to the Land of Light, instead hailing from the fallen Planet L77 of the Leo constellation, where he and his brother Astra were royalty. After his planet was destroyed by Alien Magma and his twin Giras kaiju, Leo traveled to Earth, intending to make it a second home. While there, he blended into human society as Gen Ohtori, and became a gym instructor at a fitness club for children. But, when the Alien Magma that destroyed L77 came to conquer Earth, he was forced to take action. Leo met Ultraseven during his initial fight against Alien Magma, and became the first Ultra Crusader of Earth to not hail from the Land of Light. Unlike most of the previous Ultras to visit Earth, Leo's fighting style specializes in martial arts giving him far greater physical abilities than any other known Ultras. Despite his foreign origins, he, along with Astra, were readily accepted into the pantheon of the Ultra Brothers. During his tenure on Earth, Leo and Seven became very close, and it was for this reason that Seven would eventually entrust the training of his son Ultraman Zero to Leo and Astra.

In a fight between two giant monsters named Takkong and Zazahn, young race car driver Hideki Go is killed while trying to rescue a little boy and a dog from the falling rubble. His valiant sacrifice is noted by everyone, even his friends and the new defense force MAT, but an unseen being also takes notice. Looking over Go is the "New Ultraman", who is so touched by Go's actions that he decides to combine his life force with that of Hideki, thus bringing him back to life. Hideki Go then joins the MAT and fights alongside them and Ultraman against monsters and alien invaders.