Sure, everyone knows the story of Super Mario. But what's going on in the head of his brother, Wimpy Luigi? In this part of the Super Mario Diaries, Luigi and Mario stumble on the mysterious Koopa Castle Z8654-B, in which they encounter a new and dangerous enemy named Wario. Will Toad, Mario, and Luigi be able to overcome this new challenge, defeat the greedy and villainous Wario, and continue their quest of liberating the Mushroom Kingdom? Or have they finally faced the enemy they cannot beat?