The project reimagines the historical castles in Japan as giant robots that transform and combine. In particular, the above short features the Kumamoto, Takamatsu, and Aizu-Wakamatsu Castles. A group of children and the Shirodama (the castles' souls, who are actually historical army commanders) join forces to pilot the castles.
Unfortunately the movie Castle Combiner Oshirobots is not yet available on HBO Max.
| Directing | Masami Obari | Director |
| Sound | Masami Obari | Sound Director |
| Visual Effects | Takeru Nakajima | Animation Director |
| Visual Effects | Yukihito Ogomori | Character Designer |
| Writing | Keisuke Ukai | Writer |
