To start though I want to give some info that is just something that occurs in game.
- [+] spoiler
- In Corpse Party Rebuilt/PC-98 there are 10 letters to be found. Mostly just giving hints about the incinerator puzzle. But 9 and ten are a bit more significant. upon finding them they read as this.
"Wh what just happened?"
"Like I said... ...zaki from Class 2-9 suddenly appeared!"
"Ahh... you mean that girl who went missing a year ago? She..."
"told you her name?"
"Her body... it was burnt up..."
"I'm asking you who she is! Did you get her name!?"
"You really want to know?"
"It was...Class 2-9's ...Shino..."
A common theory, is that these letters are a troll because you read then with Ayumi in your party. That if you read the same letters with Naomi in or whomever in the party it would say their name. Now that is false. For a couple of reasons.
1. if that were the case why does it say Ayumi's name and not Yoshiki's Why does it not say Kishinuma? He is typically the character shown why you read it.
2. more importantly and what I think proves that these letters are not there to mess with the reader, is a news paper on the third floor. It reads
School Newspaper: X Month 24th Day,
Today, Class 2-9's ___ki...
Suddenly... went missing.
this can only be read by Satoshi's group. Yet it still implies Shinozaki though she is not in the party. Typically I would think this was an error, an oversight. But there is an attention to detail in this game that makes think otherwise. As well what is Sachiko's name?
Sachiko was not named as such yet. But in later games does have a name. I would argue that rather than an oversight this instead was mean to give a hint towards the identity of the Vengeful Spirit and her possible relation to Ayumi. In modern corpse party they are from the same Shinozaki family and I think that began before Sachiko was even named.
As well if you were not aware, Ayumi has the Black Book/Dark Tome with a crazy idea to revive her friends in ending d-2 we later game to know of this as the book of shadows. Keep that in mind as I get into the theory.
Now for the Theory
- [+] spoiler
- Lets talk about Fact Loop. Fact Loop reverts time but fate cannot be avoided. Cool.
So now we get into "What if" territory. So as we are aware. Rank A of the original game was the "canon" ending. It was to lead into Corpse Party 2 Satsuki's Heart. Again, cool. So lets think about that the Book of Shadows was in Ayumi's family. She was able to get it in ending D-2, so now we get into where this connects with the modern series. So lets say Ayumi and the Vengeful spirit are of the same family as implied by the game and as we know in the modern games. Instead of Yoshie dying however only her daughter dies/killed/burnt/went missing.
Since we know in modern canon that the Book of Shadows is passed down through the Shinozaki family since they were hunted as witches, rather then the book going to Yoshie's daughter who is dead, it would go to Ayumi's grandparents and then parents, having the Book of Shadows in Ayumi's household.
With this all in mind lets think about Ayumi and her connection with the Vengeful Spirit. When back in the classroom she empathizes with the girl in red. Makes sense. Ayumi is known to have a heightened spiritual sense. Now underneath the school the Girl in Red, grants her power to our protagonists in order to fight the Vengeful Spirit. So after the gang escapes the closed spaces, everyone goes home.
Ayumi is known to have crazy occult ideas. So what stops her(with her new gained power to which she helped fight the spirit) from reverting time to attempt to keep the Girl in Red from dying. Again this is a theory. But lets say that did happen. Well. If we account that with fact loop, the same fate cannot be avoided, but different actions can occur. For example in Book of Shadows with Naomi and Seiko. then even if a fact loop was created then, Sachiko still dies, still becomes the master of Heavenly Host by some means, and our 5 students get pulled into heavenly host and make it out alive. This would account for why only the 5 students make it out at the end of Blood Covered and Mayu, Shige, Seiko, and the teacher all die. Completing the fact loop.
In this theory Blood Covered is part of a fact loop, and the original game started it all. Funny enough to my knowledge that doesn't conflict with the current canon. Everything that we know happened can still happen. As the loop would have been complete at the end of Blood Covered. The timeline moves forward to where we know it to be now.
Now real talk, this all assumes that either Ayumi or the spirits of heavenly host created that 40 year loop after the original game. This is a quite wild theory not supported all that much. But I think its interesting as it would tie together the original game to the current games.