Identify Help identifying a game

CmyNutt95

New Member
Dec 26, 2018
4
1
I am looking for a game I have played in the past.

Main character is a guy, for whatever reason he is singing in the shower and is transformed into a girl. He can swap back and forth between and girl and a guy buy using the special phrase from the lyrics to the song.
I believe at the start of the game his sister has disappeared, and he must use his female form to get information about his sisters whereabouts.
He has several friends helping him including both girls and guys.
At one point he plays tennis against an older man in order to get information.

Any help identifying would be great.