Seventh Heaven (1) Mio to Mio

is the first volume of the Seventh Heaven light novel series, written by Hiroyuki Domon and Illustrated by Fujimoto Hideaki. It was released under the Dengeki Bunko Imprint in February 1997.

Synopsis
On a rainy day, Mio Ikukata, who transferred to a famous elite school under the control of the United Nations, Holy Aru Kagakuin, is a beautiful 14-year-old girl who is full of energy! It was a school founded under a terrifying secret. And there she meets Mio Kurosawa, a beautiful girl with glasses who is one year older. The existence of the foggy dome "Sacred Land" that leads to another world, and the flashy battle scene that summons and fights the odd-shaped monster "Magic Beast"! More unique beautiful girls & beautiful boys !! 1st Dengeki Game Novel Award The new series presented by Hiroyuki Domon, the winner of the "Grand Prize", has finally begun.

(source: Amazon JP - Translated)