Riku is a fictional character from Square Enix's franchise Kingdom Hearts, debuting in the original 2002 Kingdom Hearts game. Riku is introduced as a teenager who wishes to visit other worlds with his friends Sora and Kairi. After a way to other worlds is opened, Riku meets the evil fairy Maleficent who pits him against Sora, leading to Riku falling to darkness and ultimately being possessed by Ansem, Seeker of Darkness. Riku is freed thanks to Sora and returns as a protagonist in following games.

Kingdom Hearts III is a 2019 action role-playing game developed and published by Square Enix for the PlayStation 4, Xbox One, Windows, and Nintendo Switch. It is the twelfth installment in the Kingdom Hearts series, and serves as a conclusion of the "Dark Seeker Saga" story arc that began with the original game. Set after the events of Kingdom Hearts 3D: Dream Drop Distance, returning protagonist Sora is joined by Donald Duck, Goofy, King Mickey, and Riku in their search for seven guardians of light as they attempt to thwart Xehanort's plan to bring about a second Keyblade War. Their journey has them cross paths with characters and visit worlds based on different Disney and Pixar intellectual properties.