A Hatsune Miku: Colorful Stage! doujinshi featuring Hatsune Miku and Megurine Luka.

In an empty “Sekai”, Miku witnesses Mafuyu and Kanade having sex. Miku wants to know if what she saw was happiness and it’s up to Luka to satisfy Miku’s sexual urges so she can understand what she saw. The power of the “Sekai” also causes a certain “surprise” to also appear from Miku’s inner desires…