Keiyaku Kanojo ~Shinmai Kanojo to Hajimeru, Tottemo H de Pure na Ren'ai Lesson~

This unusual eroge tells the story of a lonely young man whose life takes a turn for the awesome when a cute girl climbs out of his desk drawer and declares herself his girlfriend. She's determined to make a man out of him and will do whatever it takes to bring him happiness. Enjoy tons of romantic and erotic events with this beautiful and devoted heroine. A rare single-heroine focused eroge.

[From J-List]