Yuuki Miaka and Hongo Yui were two ordinary junior-high school students preparing to take the juken (high school entrance exam). One day, at the National Library in Tokyo where Yui was returning a book, Miaka follows a brilliant red bird into a room that is closed to the public. Yui finds her and there they discover an ancient Chinese novel entitled Shi Jin Ten Chi Sho ("The Universe of the Four Gods"). Yui begins to read aloud from the book and the two discover that the book is actually a magical incantation.
"When the page is turned, the story will become real and begin," Yui reads.
As soon as the line was read, the two were transported into what looked and felt like ancient China... and the story began. The two are seperated after being saved by Tamahome, a seemingly kind (but money loving) passer-by with the mark of 'ogre' on his forehead. Miaka chases after him, thinking perhaps the lost Yui had been kidnapped by him, but in fact, Yui had been returned to the real world.
While chasing after Tamahome, thinking he might know where Yui is, Miaka discovers she is in a country called Konan. While there, she is saved, again, by Tamahome, who then agrees to help her find Yui. However, the two are arrested.
The Emperor, upon finding that Miaka, is in fact, from another world asks Miaka to become the Suzaku no Miko (Priestess of Suzaku.) If she can gather seven Seishi, seven people who have been chosen by the god Suzaku to act as her protectors, she can call upon the god to grant her 3 wishes. The Emperor asks that she use one of the wishes to save his country from the greedy Emperor of Kutou, the rival country, protected by the god Seiryuu, who wants to invade Konan.
However, Kutou later finds the Miko for their god. Yui-chan becomes Seiryuu no Miko, Miaka's enemy, through a cruel set of misunderstandings which threatens to tear them apart forever.
Best friend pitted against best friend, and the beginning of a love between a Miko and one of her Seishi that will be put to the test so many times...
Open to Infinity is credited for this background info on FY. ^_^