The unnamed principal
of Sainan High is well-known throughout campus as a pervert. He will enroll any girls into the school body so as to ogle and grope them without hesitation (though, according to him, they have to be "cute girls"). This groping is not limited only to Sainan High, but in public, as well. A common gag involves the Principal spontaneously shedding his clothes and chasing after a girl he becomes smitten with, which inevitably results in him beaing beaten to a pulp. Once, Run purposefully causes herself to change into Ren to get the principal to leave her be; upon seeing Ren, the principal thinks briefly, then continues to chase him (stating "This is okay too").
Throughout the series, the principal has survived many severe injuries and attacks. Some of these include burning, (by Kyouko) beaten up, and on one occasion, almost eaten by a crocodile in the Amazon.