Neku's appearance is the same as he appears in The World Ends With You. He is seen as tall and slender, with spiky orange hair and blue eyes. He is shown wearing a sleeveless shirt with a funnel-shaped collar, and a blue-violet stripe outlined with gold going down the middle. He wears his signature blue-violet pair of headphones. He also wears a yellow sweatband on his left arm, and white shorts held up by a loose-fitting belt. He wears black shoes with a blue-violet stripe outlined in gold.
Sora is seen in Traverse Town calling out for Riku, but finds Neku instead, who is hanging from a nearby roof. He jumps down and shows Sora the timer on his hand, and mentions he needs a partner to play the Reapers' Game with. He shows his hand, revealing he has just over 43 minutes to win the game or die.
He is accompanied by a Spirit Dream Eater called Necho Cat. He has strayed from his partner and since Neku says that having a partner is necessary in order to win the Game, Sora helps him out, though he doesn't really understand the Game.
Neku Sakuraba is the main protagonist of The World Ends With You. An antisocial teen, born and raised in Shibuya, Neku despises people and acts cold towards anyone that tries to communicate with him, to the point of resorting to the use of headphones to put up a distance himself from everyone around him.
One day, Neku wakes up in the Scramble Crossing, unable to remember anything but his name. He is then forced to make a contract with his partner to survive in the "Reaper's Game" by doing daily missions assigned by the Game Master, battling against the monstrous Noise and the Reapers who serve as the game's enforcers. Neku is later forced to play two more weeks of the Reapers' Game, uncovering the secrets behind Shibuya, his lost memory, and the Reaper's Game itself.
- Neku is the first character that is not an original character, Final Fantasy character, or Disney character, to appear in Kingdom Hearts. However, he originated from the game The World Ends With You, which was conceptualized by Tetsuya Nomura and Square Enix. Neku is voiced in the game's Japanese version by Kōki Uchiyama, who also voices Roxas and Ventus.