PC-88 and PC-98 have a large collection of erotic games with the best pixel arts. The games are fun too if you can read Japanese or someone kindly provided a translationed version.
Yes this cool looking cyberpunk looking game was an adult game.
Here's an overview video that I watched at one point that shows a bunch of examples of such games and talks about the history of the platform (note some images and language are a lot less safe for work): https://www.youtube.com/watch?v=OVpX2y6KjwA
Not like this stuff is peculiar to Japan. There was an Atari VCS game where the player plays General Custer and the goal is to rape a Native American woman without getting shot by arrows.
