Fushigi Yuugi
Genbu, turtle/snake of the north.
Byakko, white tiger of the west.
Suzaku, phoenix of the south.
Seiryuu, blue dragon of the east.
They are the four animal gods of the mythical book "The Book of Four Gods' Sky and Earth". Each god desires a Miko, a priestress, to serve them. The book holds magical powers that enable this to happen. It is capable of teleporting a normal, everday girl from the real world, our world, into the book and have her become a Miko and try for the wishes her patron god could give and grant to her, with a price…
The story starts for us after Genbu no Miko (Genbu's priestress) and Byakko no Miko (Byakko's priestress) have already been chosen. Suzaku no Miko and Seiryuu no Miko are two normal girl classmates who've been selected to receive this mantle. Being teleported into the book, the two friends find themselves going through hardships and adventures, realizing dreams they're never thought of. A bitter incident splits the friends apart, and they feud against each other, trying to find all seven of their seishi, seven star warriors who are appointed be the guardians of each Miko and help her summon her god, first and be granted three wishes that their god would give…
This incredible 18-book story's written by Watase Yuu and consists of 52 anime episodes.