while I understand the reason why Kiyozumi is overly obsessed over Akari, but it's still overreacting to forced her to marry you after you meet her. she should explain everything first. of course Akari will feeling creeped out by the sudden appearance of marriage certificate inside her locker without know anything about it lolz
anyway, whether this is the hand of fate or not, I know how genuine Kiyozumi's feeling toward Akari and the reason behind it. I more invested on their relationship. now it's Akari's turn to accept Kiyozumi's feeling afterwards.