Kingdom Hearts: Chain of Memories

Kingdom Hearts: Chain of Memories is a Game Boy Advance sequel to Kingdom Hearts. It was published by Square Enix, and developed by Jupiter, and was released in 2004. It was the second game to be released in the series, and it is the third game in the timeline, after Kingdom Hearts Birth by Sleep and Kingdom Hearts, and takes place during Kingdom Hearts 358/2 Days.

Plot
Sora, Donald, and Goofy walk down a long path that seemingly goes nowhere. They see Pluto and start to follow him. He leads them to a series of crossroads. While deciding which path to take, a mysterious man in a black cloak approaches Sora and speaks to him, but at that moment, his words are incomprehensible. The path becomes one and leads them to Castle Oblivion. The cloaked man appears as they enter the castle and gives them a card. They use the card to proceed through the castle. The first world they go to is Traverse Town, where they discover that Leon, Aerith, Yuffie, and Cid have forgotten all about them, yet they strangely remember Sora's, Donald's, and Goofy's names, where Yuffie comments, "You're not in my memory, but my heart remembers you." After Leon gives Sora a tutorial on fighting and gives Sora a Simba summon card, they leave Traverse Town.

The man appears once more after they arrive on the next floor. Another cloaked man appears and introduces himself as Axel. Sora battles him, and when Axel is defeated, he gives him more cards, disappearing soon after. Sora, Donald, and Goofy go through each floor, experiencing their memories, all of which are somehow distorted, each in a different way. They start to lose their memories. A Nobody named Naminé begins to replace memories of Kairi with fake ones of herself. It turns out she is good and is manipulating his memories under the orders of the head of the castle, Marluxia. This escalates to a final battle in the end, for Sora's life, and Naminé's freedom.

Meanwhile, Riku awakens down in the castle, and as he goes up the basement levels of Castle Oblivion, he must take control of the inner darkness inside of him, dealing with Ansem, the Riku Replica, and three members of Organization XIII Vexen, Lexaeus, and Zexion, along the way.