First, let me give a brief overview of how Persona 5’s files are organized, to help explain what makes these assets suspicious. All of the locations in the game — “fields” — are referred to by a specific area code depending on what location they correspond to. For Palaces, the field codes look like this:

Kamoshida’s Palace: x51 and x52

Madarame’s Palace: x53

Kaneshiro’s Palace: x54

Futaba’s Palace: x55

Okumura’s Palace: x56

Sae’s Palace: x50 and x57

Shido’s Palace: x59

Sae has two codes for the version of the Palace in the opening (x50) and the full version (x57), and Kamoshida has two codes for… reasons. You might notice that the codes jump from x57 to x59; the unused environment file and enemy dialogue that refers to Akechi as the Ruler is labeled x58, suggesting his Palace was going to happen between Sae and Shido, or at least that it should be there in the files. However, there are no models or textures associated with code x58… but there are some files located suspiciously close to where it should be.

Please note that only the bolded parts of the asset name comprise the actual file name. Anything else is a descriptor I’ve added to give these parts more reference-able names.

　　　　　 　　 　　【Fields】

f059_050: Early Castle Throne Room

Out of everything here, this is probably the most suspicious, because it’s 1. part of a castle 1.1 with a chess motif and 2. it’s located right at the start of Shido’s Palace before any of the assets clearly associated with the Ark appear. My gut instinct is that this is some kind of Boss Arena — maybe the chess board would be the treasure? Maybe you would meet Akechi / Akechi’s Shadow sitting on the throne? It wouldn’t be the first time in the franchise where you fight the actual person in their dungeon (re: Persona 4) and it wouldn’t be the last (re: Persona 5 Royal) — but l don’t know of any good way to determine what exactly this is.

f059_051: Throne Room Hallway

Judging by the red colouration of the floor, this asset looks like it connects to the Throne Room. Like the Throne Room and all of the following field files, these ones appear earlier than any of the rooms actually used for Shido’s Palace.

f059_040: Elevator and Sewer Room

Originally, I thought this was a concept stage for the bow of Shido’s ship, but I don’t think that makes sense because the corridor along the side would be outside of the ship if that were the case. Furthermore, I think the white hallway connects to f059_042, judging by the shape and composition of the two fields, which would be even stranger for Shido’s Palace since that walkway would be way outside the boat. I think it also connects to f059_041 along the large flat orange section on the opposite side of the elevator.

Calling this the Elavator and Sewer Room because the tall golden pipe matches a lot of the early elevator objects, and, based on my understanding of what the colours correspond to, orange is for wood/brick, yellow is for metal, black is for water, and white is for generic surfaces; I think this field / Palace has a water feature.

f059_042: Sewer Room Extension

This is a really sparse field, but I think it must be a part of this Palace complex because it looks like it matches f059_040.

f059_041: Roundabout with Chess Paintings

Funnily enough, this asset was the loose thread that caused me to dig deep and find the rest of this stuff. I was originally just looking for unused textures in Shido’s Palace, and happened to stumble on chess.dds and Chess_King.dds, and while I was trying to figure out where or if they were used… lo’ and behold: some really suspicious stuff was lying around.

Some of the white pieces from f059_050 are missing… I’m honestly not too sure what that means, but it’s notable to me that these two fields have a recurring chess motif because this isn’t something you see in any other Palace’s iirc. This is one of the main reasons I don’t think this is an early version of Kamoshida’s Palace, combined with the suspicious placement and suspicious texture names.

As an exercise for the viewer: what might be the significance of all of the pieces except the King being stained red, along with the notable absence of the Queen?

050 and 051 might also be on a different floor than 040, 041, and 042, which could explain the naming conventions?

【Untextured & Simple Objects】

〔m159_040.gmd〕　　〔m159_035.gmd〕　　〔m040_003.gmd〕

The spears have an animation where they lower; the security camera’s main texture references a Field x40 which, along with the following door, is one of the only references to the nonexistent Field x40.

【Textures & “Catsle” Door】

〔m040_010.gmd〕　　

〔f040_door.dds〕　

　〔f040_misc_01.dds〕

This door is probably the most interesting thing here, at least to me, because it’s clearly in the early concept stage. The images on both textures are, according to a reverse image search, from assorted Japanese and Chinese reference image sites. Furthermore, the model has been mapped such that you can easily move parts around to see what it looks like with different parts. Natively, it just uses the white door and the dark decal, but by moving around the texture map and scaling certain parts, you could easily tweak the door until it uses the golden door or lion decal, for example.

Although this particular version of the door appears as one of the three line models that reference the mysterious Field x40, it appears twice in Okumura’s Palace and thrice in Shido’s Palace (in tex056_001_00_00, tex056_101_00_00, tex059_001_00_00, tex059_040_00_00, and tex059_042_00_00). Additionally, the texture and normal map for the Greek-style etchings on the top of the door are labeled as f040_catsle_04.dds and f040_catsle_04_NRM.dds. This door was likely designed for a castle-themed Palace; however, it never appears with Kamoshida’s assets, only by itself or with Okumura and Shido.

As an aside, I think there are some oddities with various naming conventions going on. I won’t go into too much detail here because I’m working on documenting everything on TCRF (which is… reaallllly a work-in-progress). In short: it looks like the opening Palace was going to be completely different, and for some reason there are assets that look like they should be in Futaba’s Palace that are labeled as Field x50 (which is doubly strange because even the casino parts use textures with the code x57 like the rest of Sae’s Palace; nothing in the final game uses x50 for textures). Since everything seems to be in a messed up order, and since I think only like 15% of the text, dialogue, and audio from the prototype has been translated, there could very well be more than this.

Please keep in mind: this might all be confirmation bias.

I went into the datamining project knowing that Akechi had an unused Palace, so it’s entirely possible that all of this is just unused parts of Shido’s Palace. However, I think the really suspicious thing that leads me to believe it might not be is that unused door, simply because it’s textures directly reference a field that doesn’t exist and indicates that the unused field was a late-game castle Palace. Still, there’s nothing that outright confirms where any of this came from, so again: bolder sized piece of salt.

As a closing note, I’d like to point out the irony that, of all the characters it could have been, it just had to be Akechi whose Palace would end up being such a pain in the ass to find.