You are a Japanese young man named Minoru Nakagawa. One day you notice a beautiful girl standing under a blossoming sakura tree, the sakura leaves falling around her. Amazed by the beauty of the girl, Minoru decides to follow her. Once she enters her mansion, she drops a medallion. Minoru feels that his destiny is linked with the girl's one, and in the night, he enters the mansion... Intruder is an erotic anime-style adventure. The interaction is done through verb commands. To the right you see the map of the mansion, but you move also by selecting a destination from a menu. If you are caught, the game is over, so you should plan your movements around the house carefully.