Invaders of the Rokujouma!? Collector's Edition 1 (Light Novel)

Contains Volumes 1-4!
Koutarou has just moved in to room 106 of Corona House. It's everything he could have hoped for on his budget... except for the strange girls who keep appearing to try and take it from him!
With the Corona Convention in place, the invaders are now forced to try and work things out peacefully. But when playing cards gets boring, they decide that their next battle for control of room 106 will be... at the school sports festival?!
Summer vacation is here, but it's going to put Koutarou and the invaders' patience-and their friendship-to the test. When their beach trip goes awry, will they have what it takes to cooperate when one of their own is in danger?
Koutarou and the invaders get involved with the school play for the cultural festival, but they've attracted the attention of a different kind of invader. Another princess from Forthorthe has come to sabotage Theia's trial, but lurks in the shadows before making her move!