Yuuki Miaka and best friend Hongo Yui are lured to the Important Documents Room in the National Library by a mysterious red bird that Miaka saw. They open a book called the Shijin Tenchisho, or Four Gods of the Earth and Sky, and start reading. Suddenly they get transported into the story. They are attacked by bandits but a young man with the character Oni (ghost/monster/ogre... I can't give an accurate translation) saves them. But without Miaka's knowledge, Yui gets transported back to the real world. Miaka follows the y oung man, whose name is Tamahome, to find out more aobut Yui. In the meantime, Yui is back in the library reading about Miaka in the Shijin Tenchisho. The story is about a young maiden from another world who will summon the sacred beast Suzaku and save the country. Dunno what I'm talking about? Maybe this link will help!

This anime series is complete with 52 episodes and 2 OVA series.