Bowser's Fury
Join forces with Bowser Jr. in a free-roaming 3D adventure to stop his father's rampage. Run and jump across a series of islands to collect the mysterious Cat Shines, and battle the colossal Fury Bowser when he emerges from the water to wreak havoc.
Story
On a bright and clear day, Mario walks along a path in front of Peach's castle, near the place where he found the broken Clear Pipe at the beginning of the main campaign. He notices small puddles of black goo on the path and follows them. Finally, he stops at a mass of black graffiti shaped like Shadow Mario's logo from Super Mario Sunshine. The graffiti expands to form a portal through which Mario falls and is transported to Lapcat Lake, where a rainstorm is currently raging. Shortly after Mario lands, he encounters Bowser, who has transformed into a larger and more powerful form known as Fury Bowser. Mario finds a Cat Shine in the area, which wipes the slime from a nearby lighthouse. Fury Bowser is blinded by the beam of light emanating from the lighthouse and retreats into the Fury Sun in the middle of Lapcat Lake. Immediately after, several islands emerge from the water. After Fury Bowser retreats, the storm subsides and Mario finds a panicked Bowser Jr. explaining why Bowser has transformed. He shows Mario a picture he drew of his father and paints it black with his magic brush to show that Bowser Jr. was the one who corrupted Bowser. He realizes that both he and his father are in trouble and reluctantly asks Mario to help him, but makes it clear that this would not happen under normal circumstances. Mario agrees, and Bowser Jr. accompanies him for the rest of the adventure.