Cosmos from various planets attempted to invade the Earth, and the Earthlings organized earth defense force to fight against it. It was originally Sai Wen, a star observer of M78 Nebula 34, who came to the Earth to make an orbit map. Staying on the earth to fight, he changed his body shape and was determined to fight the invaders from the universe to the end.

among all Altman's works, Ultra Seven's production level is representative. In particular, stunt production and story content are greatly innovative than before. Severn Altman's opponents are all highly intelligent cosmic people and fighting cosmic robots, so Ultra Seven is flexible and good at intelligent tactics. In addition, another notable feature is that his body can change freely, such as fighting with capsule monster after miniature, which is also his characteristic.

Ultra Seven, who left the earth, is guarding Saturn. But then the twin monsters invaded the earth, and Ultra Seven came back to the earth, and his right leg was injured in the battle. So the clusters lost their ability to transform. In order to make Ultraman Leo truly become a powerful warrior, the star clusters, which are already the captain of MAC, exercised Leo with "devil training".

Later, the Disc Creator attacked the MAC team, and the MAC team was completely annihilated except Gen Ohtori. At this time, the group let Gen Ohtori escape, and his life and death were unknown. Round Valley Company explained that the group was not dead (in Leo, the group exchanged Otto glasses with Xiang for the monster planet, which proved that Round Valley Company had the move to revive Severn), and it was able to regain the power of Severn Altman and give Ultraman Leo a dream. Round Valley Company shot several OV versions of sequels of Saiwen in his childhood, and he also appeared in Mengbius Altman later.