Invaders of the Rokujouma!? Collector's Edition 3 (Light Novel)

Contains Volumes 7.5-8.5!
Read the story of what happens to Clan and Koutarou after being sent through space-time. Will they be able to put their fight aside and work together in a strange time and place in order to set history straight, help found an empire, and make it home safely? And why does everybody thousands of years ago look so strangely familiar...
Meanwhile, in the present, Koutarou and the girls are all set for a school trip to a ski resort with their whole class-including Aika Maki. Yurika notices she's sneaking into the mountains to use magic and goes to investigate, but is totally surprised to find a demon!