Kingdom Hearts II: The Novel

Sora, Donald, and Goofy have defeated Ansem and restored the world. But beyond the dark door—a door that had to be closed—Riku and King Mickey remain. And so the trio set off again on a new journey to find Riku and the king. As they progress through the Castle of Oblivion, encountering agents from the mysterious organization along the way, Sora and his friends begin to lose their memories. What does it mean to hold, something dear? And in the end, what path will Sora choose?! (Source: Yen Press)

Roxas is the protagonist of this story. Number XIII of the Organisation. He has no memories of the time before he became an Organisation member, and so as he performs missions every day, he has doubts and questions about everything around him. He is able to wield the keyblade.

Sora's journey in Kingdom Hearts II has drawn to a close, and now a new tale is set to begin. Jiminy Cricket is looking over the journal he used to document his first adventure with Sora when he discovers a mysterious message. He didn't write it - so how on earth did it get there? King Mickey is determined to find out, so he and his friends decide to digitize the journal and delve into its deepest secrets. Inside this “datascape” dwells a second Sora who is about to embark on a grand adventure of his very own. (Source: Amazon)

Side story series to the Kingdom Hearts II novels.

In the quiet little hamlet of Twilight Town, there lives a boy named Roxas. He and his friends Hayner, Pence and Olette are trying to enjoy their final days of summer vacation, when strange things begin to happen. First the group is falsely accused of stealing photos from all over town. Then they are attacked by bizarre, white creatures. But the oddest occurrences are the recurring dreams Roxas has of a boy named Sora, and the presence of a girl named Naminé, who has a mysterious secret to share with Roxas. (Source: TOKYOPOP)