UNDEAD is looking for a retreat from the summer heat, and Ra*bits also seem to be looking for a spot for their summer camp. The summer lessons are a bit liberal!
Summer Camp (サマーキャンプ, samā kyanpu) is an event story released on Jul 15th 2016. It could be obtained through point rewards during Summer of Clear Skies! Summer Camp event and is free to read on Basic in ! mode.