The main character is you! You've befriended an Asian girl in her early 20s who has studied in the US since she was in high school, but was unable to get her green card. Over the years, you've become good friends, and she has asked to be your "fake wife" in order to get American citizenship. Of course, being a good friend (and also having ulterior motives) you agreed! It's up to you how the story will turn out. You can make your wife truly fall in love with you, or if you make "mistakes", she will become promiscuous.
In order for you to be able to install this game, you need to enable (allow) installation of applications from unknown sources (Unknown sources) in the phone settings. Usually this item is in the Security section