RapeLay is a 3D eroge game developed by Illusion, a video game developer known for making 3D eroge games. Japan rarely bans video games due to being one of the leading video game producers in the world so that fact that this game got banned domestically and not just overseas is saying something. The title is already indicative of what type of game it is (it's wordplay of 'rape play').
This is honestly one of the evilest games ever made. Just a disclaimer: I'm in no way saying anyone who enjoys this game must be sick in the head or loves the idea of raping people because there's something called guilty pleasures.