Saya no Uta

A horror visual novel where you follow Fuminori Sakisaka, a medical student whose brain injury rewires his perception completely. After the accident, he sees everyone and everything as rotting meat—pulsing organs, slick tissue, decay. Buildings look like slaughterhouses. Friends appear as shambling flesh-heaps. The one exception: Saya, a girl who looks human to him. The story tracks what happens when someone who can't perceive reality normally forms attachments and makes choices. It's a psychological horror piece built around body horror imagery and moral descent. Short runtime, branching paths, extremely graphic content. Not for everyone, but it commits hard to its premise.