Abyss - a different world of girl

Day-to-day hero was bored in life: Your pick up the book on the way home of the school.
The book in this that you can receive a summons from another world, Your response to the summons.
It met with summoned earlier than a princess of the country.
The country was destroyed by Satan to be taught to have the summoned as a hero to defeat the devil.
And weapons of the legendary class to defeat the devil, ... to the capture of the tower of the ordeal that St. sword Iryushion has been enshrined.