While Tsuchigomori seems like a normal, caring and sort-of-meek teacher in his disguise, he is actually sarcastic, mischievous and quite short-tempered. He's also shown to be quite sadistic, having fun in threatening and scaring Nene and Kou ― although he quickly stops following a light warning from Hanako.

Voice Reference: https://www.youtube.com/watch?v=fpwZdQRjf2c&list=PLVxqNewsBC1CVnM_r0H5USDaTMWLeytlf&index=6