Kooprina is a female Koopa that lives with her farther Koopal near the Sparkling Marsh. Luigi appears and she sees him and gets excited because she is a big fan of Luigi. She then asks to join and Luigi accepts.Koopal then asks her father if she could join Luigi on his adventure he says yes as well. Luigi then asks her father if there is a way to get to the bottom of Sparkling Marsh. Koopal then explains that they own a submarine and decide to take him on it so that the can go underwater. Then Koopal and everyone else aboard the submarine. They then try to find King Swamp Guy's Castle.