Tidus is a character in Square Enix's Final Fantasy series and the main protagonist of the 2001 role-playing video game Final Fantasy X. Tidus is a 17-year-old from the city of Zanarkand who is transported to the world of Spira following an attack by the creature Sin. Shortly after his arrival he meets and joins Yuna, a summoner and her guardians in a pilgrimage to kill Sin, after learning the massive creature is his missing father Jecht. He has appeared in other video games, including the Final Fantasy X sequel X-2, the Kingdom Hearts series, and several Square Enix crossover games.

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.