The Legend of the Four Kappa is a storybook which Splinter reads to the Turtle tots. A young woman, rescued by the grown Turtles, also reads the story to her child. The book appears in the story Legends which is part of the Teenage Mutant Ninja Turtles: Black, White & Green anthology series. It is an allegory of the lives of the Ninja Turtles.
The Legend of the Four Kappa tells the story of four kappa who live in a beautiful forest nestled among rolling hills. Under the watchful eyes of Ko, Kei, Kenji and Kento, the forest thrived, and all within lived in peace and tranquility. Then one day the forest was visited by the ferocious Kamaitachi wind. The four kappa hunkered down in their protective shells to ride out the malevolent force of the storm. However, the wind contained fearsome beasts called Wind Weasels, who had terrible fangs and claws like blades. Hearing the terrified cries of their forest animal friends, the kappa knew they had to save them. Each turtle employed their own particular strengths to protect the forest inhabitants. They stand up to the Wind Weasels, using their shells to channel the wind safely away from the animals. The Kamaitachi, their attacks thwarted at every turn, were carried off with the wind and away from the forest.