The story and narrative begins with Wario enjoying his newly built castle, which is filled with treasures that he has collected from earlier adventures. An evil, sentient gem called Black Jewel, hidden amongst Wario's treasure collection, suddenly awakens and takes over the castle.

Black Jewel turns Wario's treasure into monsters, and transforms the castle into four worlds. Wario proceeds through the worlds controlled by Black Jewel, recovering his treasure and rescuing Spritelings (the creatures that had sealed Black Jewel away in the past). When Wario was traversing through the snowy world of World 4, the part where his castle was torn into four different worlds. You had bumped into Wario, and you were out to destroy The Black Jewel.

”Wah?! Huh?? Grr! Who are a’ you?? This is mah’ castle! You’re in Wario’s castle! Now a’ tell me who you a’ are!”