The Irregular at Magic High School, Vol. 13 (light novel):

The Irregular at Magic High School, Vol. 13 (light novel): Steeplechase Arc (The Irregular at Magic High School (13))

July 2096. A new year means a new summer, and a new summer means another Nine-School Competition. Just to spice things up, the participants were informed only weeks before the event that there are some massive rule changes! While everyone's running around trying to figure out what they should do, Tatsuya hears rumors that another plot might be brewing around this year's competition. As the shadows rise for the second year in a row...let the games begin!

The Irregular at Magic High School, Vol. 13 (light novel): Steeplechase Arc (The Irregular at Magic High School (13))