From the Super Mario Wiki
Cherie is a Super Paper Mario character that lives on Flipside's first floor. She absolutely adores her boyfriend, but has no idea what his occupation is; in turn, he has no idea what her age is. Cherie is a talented singer, and takes every opportunity to show that to Mario (and probably anyone else willing to talk to her). She says that her boyfriend went into the beveragarium and did not come back out until night. Therefore, her boyfriend may be Hort, who is going to the Flipside Arcade.