Civilization has been destroyed by war and pollution, but the survivors have built the last city of Ecoban. As most natural resources have been exhausted, Ecoban is powered by pollution. The citizens of Ecoban need to continue creating this pollution leading them into conflict with the inhabitants of Marr while one man just wants to clear away the clouds and see the sky.
Unfortunately the movie Wonderful Days is not yet available on HBO Max.
| Sound | Won Il | Original Music Composer |
| Writing | Jun-Young Park | Writer |
| Art | Jeong Yun-cheol | Art Direction |
| Production | Lee Gyeong-hak | Producer |
| Production | Kay Hwang | Producer |
| Writing | Jay Lender | Writer |
| Writing | Michael Keyes | Writer |
| Writing | Jeffrey Winter | Adaptation |
| Writing | Moon-saeng Kim | Writer |
| Directing | Moon-saeng Kim | Director |
| Art | Lee Seok-yeon | Production Design |
| Crew | Sam Spiegel | Additional Music |
| Writing | Yun Yeong-gi | Storyboard |
| Visual Effects | Yun Yeong-gi | Animation Director |
