High schooler Yūta Iridatsu has experienced “astral projection” i.e. his spirit has been separated from his body. He woke up in a mansion named Koraikan and met a cat spirit named Chiranosuke, who told him “You must find the Sacred Tome of Koraikan in order to return to your physical body.” While searching through corridors of Koraikan, Yūta bumped into underpants of its female residents, and doing so would, eh, create some big trouble for planet Earth.
In a world where magic is not a fairy tale but has existed for one hundred years siblings Tatsuya and Miyuki Shiba prepare to begin their studies at the elite Private Magic University Affiliated High School (Magic High School for short). Entering on different levels of the academic spectrum the two turn the once peaceful campus into a chaotic one.