Miryca

So, without further ado, How exactly did Yugi Amane changed his future?  

In the red house, remember that time when Minamoto Kou told little Tsukasa that Yugi Amane died when he was 13 years old, after he murdered him?

Well, that is pretty much how Amane’s future changed, began, the second time. Let me explain. 

As stated by Tsuchigomori, Amane's future was supposed to be becoming a science teacher at the school, correct? But what if that wasn't the case to begin with? That, the real fate for Yugi Amane is that as a result of his weak body, he dies at the age of three, a few weeks or a month (if he was lucky) after this happened.

But, since Tsukasa made a wish to the so-called God under their house, Amane's fate changed and he had the chance to grow up and be a science teacher. As for the price of his wish, Tsukasa stayed inside the house without anyone knowing. Thus, changing his brother’s future. The first time.

Everything you’ve read, should've made sense from that point on, but… since Tsukasa still is inside the red house, Amane still had a future, wouldn't that mean all the stuff that's happened in the entire manga shouldn't have never happened nor even existed? Then Kou and Nene wouldn't have met little Tsukasa in the first place, but they did. So how did Kou and Nene meet little Tsukasa despite the fact that an Amane that has a future still exists? The timeline is clearly messed up. 

However, if we ignore that for now… It would mean Amane’s future changed Three times. 

First was Yugi Amane’s true fate, which is for him to die at the age of three due to his poor health. Next is the future where he was going to grow up and become a science teacher as a result of Tsukasa’s wish. Lastly, is the future where he killed his brother and (likely) himself when he was 13 and then became Hanako-san, because little Tsukasa came back after being ‘missing’ for more than half a year after their 4th birthday.

In other words, it wasn't Amane who changed his own future, it was his brother Yugi Tsukasa. 

I believe this is what Aidairo was trying to show in the red house arc, how Amane’s fate was changed or to be more precise, how Tsukasa changed his brother's future, two times.

With nearly half of the mysteries removed from their seats, when a pit opened up, and the school became infested with supernaturals. The only way this was resolved was through the use of a kannagi, Akane Aoi, as a temporary sacrifice. This triggered the severance, which forcibly removed all supernaturals in the School from the Near Shore, preventing those Supernaturals within these boundaries from emerging into the human world. 

However, the boundary between the human and supernatural worlds is still collapsing and the only way to prevent it from happening is by sacrificing a Kannagi. No.6 has stated that as long as he gets a Kannagi to the far shore, it will end the same; the human and supernatural worlds will be completely separated.

Nene is the Kannagi, and she has a very important role to play in keeping the balance between the human and supernatural worlds. If she is sacrificed, it will bring back the balance that is so necessary for both worlds. 

Even Tsukasa and Tsuchigomori refer to her as a kannagi, implying that they are aware that she will be sacrificed in the end and that there is nothing anyone can do about it. And it was Aoi who Hanako attempted to sacrifice instead of Nene because, apart from Nene, she is qualified of becoming a kannagi due to her Akane bloodline. 

But as you know, Aoi can't be used as the kannagi anymore. The only way to remedy— accomplish this is for Nene to be sacrificed.

But before we go any further, you should recognize the difference between Fate and Destiny.

Fate is a future set in stone that cannot be changed and is often out of your control, while destiny is a future that you create based on your own actions and choices.

I assume Nene's fate as the Kannagi wasn't truly her future until she summoned Hanako. I think Nene was going to die naturally (her lifespan is still short) until she decided to knock on the third stall. Her fate was to die early, but her destiny was to become entangled in these supernatural shenanigans as a result of her choice.

Once all of the Yorishiros are destroyed, completely destroying the balance, and the only way to fix it is for a Kannagi to be sacrificed, that is when Nene's lifespan ends. She will either sacrifice herself or be sacrificed in order to restore normalcy.

Tuesday, July 22, 1969 | Nene's first glimpse of Yugi Amane's School life (I'm not sure if I should count this one, but-)

Friday, July 18, 1969 | In the School Classroom

Tuesday, July 7, 1964 | At the Star Festival

Do you see the similarities?

Nene's journey into the past all occurred in the same month of July.

Both the First glimpse and the Star Festival took place on Tuesday. And in the Classroom, with the First glimpse coming four days later, when Amane decided to give up. This all happened in July. Which is strange… why July, of all months?

I tried to find something related to this, but all I found was July being the seventh month of the year, which you know Hanako as the seventh mystery, yeah… I believe this is a foreshadowing of Amane becoming the seventh mystery by the time he meets Nene again.

(Not to mention that the Urabon/Obon took place in July as well.)

Yugi Amane's story was always one of tragedy, even from the very beginning.

I believe he never changed his fate; it was only the consequences of someone attempting to, that caused it to have an impact on his future.

According to the Red House Arc, Amane was born frail and sickly. His health never improved and there was no telling how long he would last. When Tsukasa decided to make a wish on the ‘thing’ under their house, he wanted nothing more than to grant Amane’s Wish, that is for him to be healthy and free of illness like him.

As a result, 10 years later, instead of succumbing to illness without committing any sins at the age of 3 (before they turned 4), Amane died by stabbing his brother and then himself with a knife for reasons we still not know yet. Even though he got a few extra years, it was always going to end the same way and that is with him dying but this time with a twist.

It was his fate returning to ensure he still died at a young age, despite having lived a few years longer than he was supposed to…

To summarize, Amane and Tsukasa both suffered the consequences for trying to change his fate.

So, that is why kids, you should never go up against fate because it will come back to haunt you much worse.

Be careful, Nene-chan~

But, before you scroll away, please pause for a moment and allow me to offer a quick theory as to how and why Amane may have murdered Tsukasa. Since Hanako’s knife is a Kitchen Knife, it might mean the knife was taken from his home.

(If you're skeptical, please take a look at nanabansama’s analysis regarding the knife: https://nanabansama.tumblr.com/post/640222877833134080#:~:text=so%2C as some of you,use the term 「包丁」！)

That has to give at least someone an impression that the murder took place in his home, The Red House. It must imply that the murder occurred on the same day that their parents died, leading them to believe it was a family suicide, but in truth it was far more complicated.

I assume Tsukasa may have done something to their parents (or it’s probably something else which is likely), that caused Amane to kill him and then himself out of guilt in their house.

Taking note that according to the official manga book it was a ‘Murder-Suicide’

taking items that appear out of nowhere in your clothes

(How did it even fit in there???? 😶)