Really? My moneys more on Ami. She seems more yandere-prone than anyone else.
my money is on ayane or sana... ayane has the yandere feel of killing anyone that threatens sensei... sana comes off as the yandere that would get off helping rin with the razorblade and is trying to hold it back ultimately resulting in a shy quiet personality afraid of projecting her killing intent on those around her to lure the flies into her web as a true black widow does.
... or it could be futaba "you were the only one noticed me senseiiiiiiiii"
... or it could be makoto "THAT DICK, ignore the ropes sensei but that DIIIIICK is mine now and you can't escape or deny me anymore
... or it could be yumi "how many time did I have to tell you to cut it out old man *gunshots from an illegal gun got from the yakuza*"
... or it could be molly... nah she is already that insane no need to project future insanity
... or it could be tsunyo "thank you for this meat noodle that grandpa just informed me all men have, I'm sure it will taste great in ramen"
... or it could be rin "now we all can have eternal peace together in the grave, *school shooting sounds*"
... or it could be chika "*the sounds of meat cleavers and a LONG overdue mental breakdown from having to become a parent while still a child and having the one person that they trusted tohelp carry the burden of early forced adulthood betray them in a school wide sexual romp*"
... or it could be kirin "wait... you wont fuck sensei while i get to watch, well you get to fuck this knife *screams*"
... or it could be karin "you all are having sex, you impure heathens, *knife noises*"
... or it could be kaori "From what I understand ham is made from pig, and man is called the long-pig, with the amount of hamburgers you humans eat it must be delicious... I have sampled this hamburger and must agree but how much better would it be if it was a longhamburger, I must try it starting with you."
... or it could be haruka "my husband is back... sorry but you understand, you just have to go... and he can never know"
... or it could be Sara "ok so I know you were always kinda weirded out by all the things I got you to try lately but I swear this will be the last one, this rope here will choke me while this one chokes you..."
... or it could be makoto's mom " you think these dildo's were FOR ME hohohohohohoho, you seem like a nice dragon size"
... or it could be noodles "squak squak, squak squak, *noise of deadly katana made from glorious nippon steel folded 10 billion times by talons of her long dead ancestral flock"
... or it could be cinami "you fool you have broke the illusion I cast on these two unwitting fools who feed me and cloth me for free, they now know I have been leeching of them for years, NOW I MUST FIND NEW PAWNS IN MY 5000 YEAR QUEST, DIEEEEEEE"
... or it could be miku... no... she is too pure...