From the Super Mario Wiki, the Mario encyclopedia
Blissful Beach is a location in Paper Mario: Color Splash. It is a private oasis near Bloo Bay Beach. A Mini Paint Star is located here, so Mario and Huey have to win the Blissful Beach Key by playing events at Oceanfest. After they beat Toad Shuffle and Toad and Go Seek, they are given the key and allowed access to Blissful Beach. Here, Mario and Huey can relax on the beach chairs, and the Five Fun Guys dance next to them. A purple Rescue Squad recruit is also found on Blissful Beach.