From the Super Mario Wiki
Hulu is a dance instructor in Mario Party Advance. She is a Dancing Spear Guy who runs Shroom City's only dance school, the Dance Stage, with two other Spear Guys. The dance school is located in the Jungle Area of Shroom City, and her quest is called Jungle Jive.
To clear the quest, the player has to press different buttons (B, A or the control pad) that Hulu shows on a plate. If the player clears the quest, the Mini Bowling Gaddget is unlocked. The ending states that she got new students and a new classroom.