Gackt, the Japanese musician & actor released a his own F2P mobile game "P.S. I LOVE U GACKT". The developer is Allfuz.
This is a romance sim that assumed his number "P.S. I LOVE U" a motif. In this game, Gackt appears in 2D illustrations and players can fall in love with him in various situation.
The stories are 15 kinds in total and the ending change by the choice of each stories. If players can arrive the happy ending, they can get images with Gackt's voice message and the privilege story. In addition, he has many fans abroad as well as Japan< so this game supports English. Downloading is here(iOS/Android).