It's the story of a 15 years old girl names Miaka and her best friend Yui. They were visiting the National Library when they found an old chinese book called "The Universe of the fours Gods and Skys. They beggan to read, turn the page and are pulled inside the story in the book. They were gonna be attak by some slavers but are saved by Tamahome. But a red light glows around Yui and she disapears. Yui reapers in the library without Miaka. That how it all began.