The Irregular at Magic High School, Vol. 7 (light novel): Yokohama Disturbance Arc, Part II

It's time for the National Thesis Competition to take place in Yokohama but what was supposed to be a grand event for the participating students has been turned into a battlefield. A mysterious band of armed magicians and mechanized weapons have stormed in and it may be up to Tatsuya and the others to get everyone home safely!