Originally an imageset by the hentai artist 774 (also known as Nanashi). Then LWB translated it to English and while they were at it, they also made it into a visual novel. The actual visual novel part can be accessed from the New Game option in the menu and is a kinetic novel with no sexual content. The New Game+ option leads to the same story, but with added choices and bad endings (usually nonsensical, some contain sexual content).
The release also comes with two short 3D hentai videos and a very short hentai minigame, all of them completely unrelated to the VN.
