The safest and most common method is the . Here is the step-by-step process:

Guide :: Adding Cards and Scenes to your game - Steam Community

Illusion game cards are specialized image files (typically in format) that contain all the character or scene data for games like AI Shoujo , Honey Select 2 , Koikatsu , and Room Girl . Because the data is embedded directly into the image, downloading and using them is as simple as saving a picture and moving it to the right folder. Where to Find Illusion Game Cards