Riku

Riku is the dueteragonist of the Kingdom Hearts series. He lives at Destiny Island with his best friends Sora and Kairi.

Kingdom Hearts: Light by Darkness
''Sora's longtime friend. Formerly being a wielder of darkness, Riku is able to completely withstand the darkness. He is also a wielder of a mysterious weapon; a Keyblade.''

Kingdom Hearts: Light by Darkness
Riku lives his normal life at Destiny Island--until one day, when the Heartless invade his home world. With his friends, they fend off the Heartless, and then soon afterward, Sora and Riku follow Kairi into a pillar of light, transporting the three to Twilight Town.

At Twilight Town, Riku meets Pence, and loses him, when suddenly a Darkside attacks, which lets him meet up with Kairi and Sora. They defeat it, and Sora is asked a favor. Riku then leaves to train, battling Heartless, and meets Setzer along the way. The two battle, challenged by Setzer, and the result can go either way. Afterward, Hayner gives Sora, Riku, and Kairi a letter to the Mysterious Tower, where Yen Sid gives the three a quest. Once finished, the trio seals Twilight Town's Vent.