The normal entrance to the Mushroom Suite is blocked from the inside by a vine. To the left of the door is a crack which Luigi can peek through to get a glimpse of the Mushroom Suite. To get into the room, Luigi must climb up the stairs, once doing so a cutscene will starts which will end up with Luigi falling down the stairs and breaking the wall next to the door which allows him to enter the room.
The Mushroom Suite is a bedroom which is split into three parts, the first, second, and third floor. Luigi starts on the second floor, which is covered in glowing overgrown vines, and glowing mushrooms. There is a bed, and a wardrobe. Luigi can break open the wardrobe using the Suction Shot to get some coins and a pearl. Luigi can walk onto the bed, and then walk onto the purple mushroom in front of the bed. Then he must do a Burst, to bounce from the mushroom on top of the bed where there is a treasure chest with some Gold Bars. Luigi can also pull the curtains on the other side of the bed to access the first floor of the room. On the first floor are some Strobe Flowers, but there is also a pipe in the top right corner which Gooigi can go through. This pipe leads Gooigi to a Strobulb with the green gem inside.
To get to the third floor of the room, Luigi must blow the wheelbarrow with the mushroom in front of the glowing vine, so that he can do a Burst and get onto the leaf above. From there he will pass a pipe, which Gooigi can go through to get a few Bills. Continuing on, Luigi can Burst from the mushroom and get onto the third floor.
The third floor is another bedroom, with a bed, hammock, a couch, and some shelves with plants on them. If Luigi flashes the Strobulb onto the hammock, he will find a Golden Goob. In the bottom left corner, next to the bed, are some mushroom Luigi can climb up tog et on top of the bed. Once up there, if Luigi uses the Dark-Light Device, he will reveal a hidden treasure chest with some money inside. To get out of the room, Luigi needs to pull the huge leaf blocking the door using the Poltergust G-00.