An alternate version of Ultraman Cosmos 2: The Blue Planet, which was created due to the arrest of the film's star, Taiyo Sugiura. New scenes were filmed that are primarily set in the past. Musashi Haruno, now a middle school student, continues to pursue his dream to become an astronaut, which is also a promise he made with Cosmos. However, he is on the verge of despair because space development gets canceled due to a rocket accident. A mysterious girl named Shau appears in front of Musashi. She invites him to a mysterious parallel space and shows him a vision of what will happen to him 10 years from now. He witnessed a crisis of Earth's destruction caused by Sandros, the worst destroyer in the universe!
Unfortunately the movie Ultraman Cosmos 2: The Blue Planet - Young Musashi Chapter is not yet available on HBO Max.
| Production | Kiyoshi Suzuki | Producer |
| Writing | Keiichi Hasegawa | Screenplay |
| Visual Effects | Tsugumi Kitaura | Special Effects Supervisor |
| Art | Tetsuzô Ôsawa | Art Designer |
| Production | Kazuo Tsuburaya | Executive Producer |
| Sound | Tatsumi Yano | Music |
| Writing | Hideyuki Kawakami | Screenplay |
| Crew | Shin'ichi Ôoka | Cinematography |
| Directing | Tsugumi Kitaura | Director |
| Directing | Tomoki Sano | Assistant Director |
| Crew | Kunihide Kuruma | Stunt Coordinator |
| Editing | Akira Matsuki | Editor |
| Sound | Kazuharu Urata | Sound Recordist |
| Lighting | Kazuo Takano | Lighting Director |
