Why Did My 2D Isekai Turn Into a Bizarre Horror Story?

Traveling to the second dimension, with both parents deceased, owning wealth and a house. Although the Cat Guest’s rules prohibit having a sister, this is clearly the trajectory of a main character in a typical daily-life harem story. Surely next comes the charming development, surrounded by girls in a wonderful story, right? Wait a second, Isn’t this script wrong? Corpse whisperings, creeping shadows, paper figures asking the way, eerie village night tours, eyes peering from under the bed… Bizarre rules weave bloodshed, inescapable, only facing the endless nightmare offers a glimmer of hope. So being entangled by these horrors, could I get a system, preferably one where just signing ...