A mysterious alien begins attacking a brutally killing MAC members. Leo must stop it.
Toru and Kaoru, friends of Gen and the MAC Team are being raised by their dad after their mother died. Leaving the MAC training facility one night, a mysterious creature kills the man in front of his kids and leaves a metal object at the scene. Gen Ohtori becomes seriously concerned upon seeing the object and notices it has the face of Ultraman Leo on it. Both Gen and Goro must now figure out who will take care of the newly orphaned siblings, Goro says he still a bachelor so he cant feed them Takeshi has his little brother and Momoko can't. Suddenly, a MAC member - Suzuki, also a family man, decides to let the kids stay with him temporarily and he also invites Ohtori comes to his house too. When they almost reach Suzuki's place, the deadly creature attacks once more, killing Suzuki in front of the kids and quickly leaves the scene. In scene, Captain Moroboshi informs Gen that the metal object has Ultraman Leo's face which the creature leaves at the scene actually was made of a space metal - meaning a alien did this and he want to ruin Gen's name by invading in Leo's guise. On another night, Captain Moroboshi is ambushed by the alien till Gen arrives and forces it to flee. Later, Moroboshi informs Gen the alien is named Tsuruk, an outer space monster with flesh-shredding blades for hands. To defeat Tsuruk, Gen must learn yet another martial arts technique to apply to his growing Leo skill set.
- Ultraman Leo/Gen Ohtori (ウルトラマンレオ, Urutoraman Reō/おおとり ゲン Ōtori Gen?): Ryu Manatsu (真夏 竜 Manatsu Ryū?)
- Dan Moroboshi (モロボシ・ダン Moroboshi Dan?): Kohji Moritsugu (森次 晃嗣 Moritsugu Kōji?)
- Toru Umeda (梅田 トオル Umeda Tōru?): Tsunehiro Arai ((新井つねひろ Arai Tsunehiro?)
- Kaoru Umeda (梅田 カオル Umeda Kaoru?): Yoshiko Tominaga (富永美子 Tominaga Yoshiko?)
- Momoko Yamaguchi (山口百子 Yamaguchi Momoko?): Kaori Okano (丘野かおり Okano Kaori?)
- Seiji Omura (大村正司 Ōmura Seiji?): Yu Fujiki (藤木悠 Fujiki Yū?)
- Takeshi Nomura (野村猛 Nomura Takeshi?): Yukio Ito (伊藤幸雄 Itō Yukio?)
Ultraman Leo Volume 1 features episodes 1-4, & Complete DVD-Box Features All Episodes.