A leak from Weibo claimed that the manga written and illustrated by Masakazu Ishiguro, Tengoku Daimakyou (Heavenly Delusion), will have an anime adaptation that will be produced by the studios Production I.G.. The leak did not reveal a scheduled release date, and it should be noted that there is no official confirmation as of yet.
It should be noted that an animated promotional video had already been produced, published in July 2018:
Ishiguro began publication of the manga through the magazine Monthly Afternoon from the publisher Kodansha in January 2018. The publisher published the seventh compiled volume in March 2022, while Ishiguro is also the author of Soredemo Machi wa Mawatteiru (And Yet the Town Moves), which already had an anime adaptation.
Synopsis for Tengoku Daimakyou
Within the safety of the walls, the youngsters are raised in a nursery environment by robots. Although life there may seem stale on the surface, the children are full of potential and curiosity. In many ways, it is like a slice of heaven. The outside world is hell. There is almost nothing mechanical and it is inhabited by strange and powerful supernatural beings. Maru, with the help of Kiruko, is out there traversing what was once Tokyo through the sky. But after searching for so long, perhaps heaven is more of an untenable dream than a potential reality.
© 石黒 正数 (著) / KODANSHA 講談社