After being sucked into a drain pipe, Mario and Luigi defend the Mushroom Kingdom from King Koopa.
In Lava Land, Mario, Luigi, Toad and Princess Toadstool use a variety of floating rafts to reach an island named WakiWaki in the middle of the ocean, where Mario, Luigi, Toad and Princess Toadstool are to meet a Fire God.
While searching for a place known as Sharewood Village, the gang find themselves lost in Sharewood Forest; as Mario, Luigi and Princess Toadstool stand nearby, Toad begins to glance at his map to Sharewood Village.
When a giant sea monster terrorizes Happy Harbor, King Koopa offers to stop the beast if the citizens make him king.
A leprechaun's pot of gold has been stolen by King Koopa.