Which Kingdom Hearts game featured the cast of "The World Ends With You"?

The game that featured the cast of "The World Ends with You" in the Kingdom Hearts series is "Kingdom Hearts: Dream Drop Distance." This game includes characters from "The World Ends with You," such as Neku Sakuraba and Joshua, as they play a crucial role in the storyline. Neku and his friends from Shibuya are part of the game's unique mechanics, called the "Reaper's Game," which challenges the main protagonists, Sora and Riku, to navigate through various worlds and dimensions. "Dream Drop Distance" successfully integrates the characters and elements from "The World Ends with You" into the vast Kingdom Hearts universe, creating an exciting crossover experience for fans of both games.