Picking up directly where Super Mario World 2: Yoshi's Island (1995) left off, After Baby Mario and Baby Luigi arrive at their destination, the Stork discovers he delivered the babies to the wrong parents and as the Stork attempts to deliver the babies to the right parents, Baby Mario and Baby Luigi are once again separated when Kamek again ambushes the Stork. As Luigi is kidnapped Baby Mario lands on a new Island filled with Yoshi's and they must once again go through several areas to rescue Baby Luigi and save Yoshi's New Island from the evil Baby Bowser.