Another/Fridge

Fridge Brilliance

 * There's a moment around episode 8, the beach trip, where everyone gets tense just as they're leaving the Yomiyama city limits and a big rig is passing them. A reasonable move on their part, up until the reveal of the final episode. There was very little chance that the big rig would cause some kind of accident at that particular moment because was there in the car with them.
 * The OVA reveals that

Fridge Horror

 * The rules of the curse are very specific. How many people had to die for the school to figure out all the little nuances?
 * A LOT, as they explained in Episode 6.
 * They've had 26 years of unfortunate practice, after all.
 * We learn that there's a way to stop the curse after it starts up, but making use of it requires being able to . Even the person who pulls it off ultimately lacks a Ripple Effect Proof Memory. So you have a method of stopping the curse that is not only unreliable in and of itself but can not be reliably passed down to future generations, making it unlikely the curse could ever permanently be stopped. Even if the above weren't true and students were able to consistently stop the curse, the memory factor means that overuse could end up causing students to forget the curse altogether, starting the entire cycle back at square one.