Definitely the pacing in this was better than the first half, which I intensely disliked because of the constant interruptions that prevented the narrator/reader from learning about the truth. This second half is more action and less explaining and waffling, although there's still some of that here to drag out the runtime.
So we learn that the only way to stop the cursed deaths from going until graduation is to find the extra person or casualty and kill them. So with a bunch of extra rules, this is like Mafia now. People in the group randomly die until the "killer" is identified and killed, except in here the "killer" doesn't actually kill people with their own hands. It's their very presence in the classroom that brings misfortune to all those in their vicinity in Third Year Class 3, because they're an anomaly. They're already dead, but their deaths have been wiped or altered from everyone's memories until the cursed year is over.
Unfortunately, the way it's set up, you cannot possibly figure out the key twist behind the book until the very end, because a very important piece is withheld from you. That is, that the assistant teacher Ms. Mikami and the narrator's aunt Reiko are the same person. I was suspicious of both of them, but it really was not possible to connect the two unless maybe you overanalyzed it to death, as it did mention they both are artists and that the senile grandpa mentioned both his daughters died. However, these clues are too subtle and it's pretty obvious the author didn't intend for you to figure it out until he finally revealed it to blow your mind. I wasn't mind blown though. My reaction was like, oh, that makes sense, but how were we supposed to guess that without knowing the fourth rule and without knowing why the narrator was so awkward with his aunt?
I would say it was an enjoyable read but because of how two dimensional every single character is, it lacks reread value. The most successful aspect of the mystery was Mei Misaki because of how weird and mysterious she is, with her doll eye that can see death. Can she be trusted? When the other characters die, you don't feel anything, because they're not really people. Just another death to add to the growing list of deaths. Besides the death of their homeroom teacher, I cannot recall any other deaths that happened until the climax, where eight people die all at once in the same location.
To be honest, I'm far more interested in the unanswered question of why did the female caretaker go on a murder spree all of a sudden. Was this something that has ever happened in the 25 years preceding this cursed year? Because it according to Mr. Chibiki, the deaths usually happen in pairs, very rarely eight in one night. And usually it's due to illness, accidents, or suicides, NOT getting slaughtered by a knife-wielding maniac. And another thing, the person who belonged to this class already died, but his grandparents were the additional fatalities here. They did so much explaining of the rules of the curse, but I'd always assumed that the classmate (or family member) who dies cannot have tragedy strike another time in their family again. Maybe that was a wrong assumption, after all. I mean, in the first half, the girl's class representative and her mother both died, but they died at roughly the same time and on the same day. But here, we have the classmate dead for several months, and then his grandparents die at the end of the book. There have been no mentions of more than two members in one family affected by the curse, with such a large gap in time between their deaths. This is also an anomaly.
Anyway, it was pretty obvious from the start that both the unreliable narrator and Mei were huge red herrings, so I never thought they were the extra person. By near the start of this second half, I already suspected Ms. Mikami, due to the frequency she's mentioned but how she doesn't actually contribute to anything. I was suspicious of Reiko, too, but couldn't figure out why. So the end made sense to me, I'd just rather the narrator revealed it earlier, because in the grand scheme of things, the two people being the same person really doesn't make it any more obvious they are the extra person. That's just my opinion though.
Looking forward to continuing this series with the next two books left!