The anime adaptation of Yasuki Tanaka’s Summer Time Rendering manga is set to release in 2022. The announcement was accompanied by a teaser visual for the anime.
The suspense anime was announced in February alongside a live-action adaptation and real escape game.

The Summer Time Rendering manga began in 2017 and ended in 2021 with 13 tankōbon volumes. Manga Plus describes the story as:
Upon hearing of Ushio’s death, Shinpei returns to his hometown of Wakayama City on Hitogashima and reunites with his childhood friend’s family. The funeral goes smoothly, but under the surface something strange is brewing on the island. What mysteries await him on this secluded summer island?
Source: Summer Time Rendering Twitter