Ultraman Leo is the seventh in the "Ultra" series saga that started with Ultra Q in 1966. It is also regraded as the final series of the second period of the Ultra series that began with Ultraman Jack ( 1971 ).
Moroboshi Dan ( Koji Moritsugu ) is the captain of MAC ( Monster Attacking Crew ). His alter ego is Ultra 7, a space patrol from M78 nebula. He was injured badly in the battle with the kaijyu Red Gilas and Black Gilas, and lost his ability to transform into Ultra 7. Ootori Gen ( Ryu Manatsu ) works for sport center as a trainer, but he's really a refugee from L77 nebula called Ultrman Leo. He comes to the rescue of Ultra 7, and that starts the relation between Dan and Gen. Gen becomes a member of MAC to battle the invading monsters in place of Ultra 7. Dan becomes his mentor, and Gen under Dan's auspices, receives his training to combat the monsters.
The series has fighting spirit as it's core theme which was part of the original concept for this series. Because of this, each episode has element of protagonists, overcoming some challenges or obstacles in their lives. The attraction of this series is having Moroboshi Dan/ Ultra 7 being the captain of MAC, which adds interesting angle to each story. It's the only Ultraman series that has constant dialog between the two Ultramen to sort out the battle plan. The series maintains the story driven style that began with Ultraman Jack.
This is perhaps the last of the classic Ultraman styled series as Ultraman series morphs into more modern looking Ultramen, and team of monster fighting squadrons. Each of the Ultraman series shows the evolution of Japanese culture, and this series presents an interesting look into the culture of Japan 40 years ago.