A few years earlier, while they are still students, Sakamoto, Nagumo and Akao are causing terror on the JCC campus. Soon, the penalty falls! If they do not want to be expelled from the Academy, they will have to carry out a very special mission... That's how they land in the department store of the assassins, in the company of Uzuki, another student of the JCC as discreet as mysterious, in order to eliminate their target!