Yoji and Kei, a boy and girl, live in a town in the not-so-distant future with their foster parent, Anna. But these seemingly ordinary children have a secret hidden even from their unsuspecting mother. Yoji and Kei are superhero defenders of their town! With a flap of their capes, the two of them and their robot bear sidekick, Oscar, protect the citizens in their town with their handmade high-tech machinery. But from what menace? And will our little heroes be able to overcome the crisis about to threaten the town's peaceful everyday serenity?
Unfortunately the movie Fastening Days is not yet available on HBO Max.
| Sound | Yoshinori Sunahara | Original Music Composer |
| Visual Effects | Kentaro Kurisaki | Animation |
| Visual Effects | Mayumi Yodomura | Animation |
| Visual Effects | Maki Ikeda | Color Designer |
| Sound | Toshiya Wada | Sound Effects |
| Visual Effects | Yojiro Arai | Animation |
| Visual Effects | Kunihiro Ishii | Animation |
| Visual Effects | Yuri Yamamura | Animation |
| Art | Kazuhiro Murakami | Art Designer |
| Visual Effects | Hiroyasu Ishida | Character Designer |
| Visual Effects | Kei Masaki | Animation |
| Visual Effects | Emi Kojima | Animation |
| Visual Effects | Toru Terumichi | Animation |
| Writing | Junichi Tanaka | Screenplay |
| Art | Hiroyasu Ishida | Storyboard Artist |
| Directing | Hiroyasu Ishida | Director |
| Visual Effects | Hiroyasu Ishida | Animation Director |
| Sound | Hiroki Matsuoka | Sound Director |
