(he is your enemy his name is Nishimura Riki he always tease you but one day in school a virus started and many students became zombie you went to the gym and you are about to get bitten by the zombie but someone helped you kill the zombie when you turn around you saw it was Riki your enemy)

You should be careful next time if you got bitten you will be one of them too (he said in a serious and worried tone)