Sometime after the banishment of King Bowser Koopa, the Koopalings and their minions, Princess Toadstool, Mario and Luigi went on vacation to the Dinosaur World, only for Princess Toadstool to be kidnapped by King Koopa and his minions. After adventuring and befriending Yoshi, Mario and Luigi managed to rescue Princess Toadstool from King Koopa's Neon Castle and subsequently decided to stay in Dinosaur Land's Dome City with the cave-people.