Premieres summer 2025. The new PV is here. Check out the ANN article for additional information. Synopsis from AniList:

Two best friends living in a rural Japanese village: Yoshiki and Hikaru. Growing up together, they were inseparable… until the day Hikaru came back from the mountains, and was no longer himself. “Something” has taken over Hikaru’s body, memories, feelings… and everything they know begins to unravel.