Why is altering the future limited to diary users?

Question

Throughout the episodes, there are several scenes that play out in a similar fashion:

Static is heard and a diary's contents are updated to reflect the updated future.

Person 1: "Did you hear that?"

Person 2: "There must be another diary user nearby"

But sometimes the things that alter the future are incredibly trivial, (like travelling to a different floor on the elevator, or not eating a salad) and theoretically anyone should be able to do them. The main reason the diary users change the future more often is because they can see certain events in advance and consciously decide to change them, but other than that, they are visibly no different from the rest of the population.

Everyone seems to have free will, and so everyone should be able to make a spontaneous decision and affect the timeline. For example, Yuki altering the future by opening the door at Yuno's house was down to his curiosity alone and not related to his diary, so surely a non-user would have altered the timeline in that same scenario.

Granted, for a diary to display the altered future, it has to correspond with that diary's output (e.g. something in close proximity to Yuki, something affecting an escape for Ninth), but that alone doesn't isolate changes to only other diary users.

So why are the diary users so confident in proclaiming the proximity of another diary user when the future changes? Why couldn't it just be a regular person altering their schedule, coincidentally coinciding with the user? And doesn't Akise change the future (as a non-user) in chapter 14 during the coin game?

Example 1

Example1

_{Chapter 11 page 27}

Example 2

Example2

_{Chapter 14 page 33}

I always considered this a bit of a plot hole in the series. I think the author was trying to have everything besides the actions of the diary owners pre-determined, even the things you consider "spontaneous decision". — Alagaros, Jul 11 '15 at 23:50
Because one diary user is trying to kill another , i think so — mirroroftruth, Jul 12 '15 at 04:47

score 3 · Accepted Answer · edited Dec 14 '16 at 14:28

The future only changes when a diary owner acts against the "reality" which their diary foretells. So the future for everyone is predefined, because they already decided if they want to eat the salad (but they don't know they did). Only if you know for sure that the current future contains you eating a salad are you able to change the future.

EDIT:

About the Akise thing: No, Akise didn't change the future. Yukiteru's diary never really tells the truth. It just tells what Yukiteru is/was/will be able to see. (It was the same thing when that little kid, Fifth, attacked them. Yukiteru was in the toilet and his diary didn't "say" anything except that it was quiet at the toilet.) So, Akise won the coin game, but he told Yukiteru that he lost, his diary will "think" he lost even though he didn't.

Why is altering the future limited to diary users?

1 Answers1