The Principal's Fearsome Idea: Starting Tomorrow, You're All Shaving Your Heads!!

Synopsis

Following the loss of his last hair, Principal Edajima decrees that all First Years must shave their heads, unless one student can perform the Head Seal. This involves writing the word "man" (男) on the Principal's head. All the attempts by the students fail until Momotaro tricks the principal into putting on a helmet with a stamp on the inside performing the Head Seal . Instructor Oni-Hige then has his own head shaved as the result of losing a bet with Momotaro. (Source: Wikipedia)