Evidence from an early Persona 5 build indicates that Atlus originally planned to incorporate cameos of characters from Persona 4. The original Persona 5 had a troubled development and was delayed multiple times before its eventual release in 2016. As a result of its development troubles, there were some things left on the cutting room floor.
A beta build of Persona 5 was leaked online earlier this week, with the build dated to December 2015. This beta included interesting details, such as early versions of cutscenes and songs from Persona 5's soundtrack, like «Rivers in the Desert» and «Last Surprise». Persona 5 modders have been digging through this beta and posting their findings online, with one discovery being characters from Persona 4 who were likely going to make cameos in the game.
Twitter user A Mudkip found that there was a fully modeled version of a grown up Nanako Dojima in the Persona 5 beta files. Nanako is a character who was the protagonist's cousin and was Persona 4's Justice social link. The pre-teen Nanako is dressed in a thick jacket and still has the pigtails she wore as a kid. She apparently has animations assigned to her that originally belonged to the female protagonist of Persona 3 Portable, wielding a racket.
The cameos don't stop at just Nanako Dojima, as another modder on Twitter, EllenZappa, discovered a model for an older version of the Persona 4 protagonist, Yu Narukami. Narukami's model is styled after Persona 4's more limited, almost chibi-like design, but his proportions resemble how characters look in Persona 5. Yu's model is incomplete, as he was only modeled up to his underwear, and no other clothing. The contrast between Yu and Nanako's models has gotten fans speculating at how these cameos would have worked.
One of these theories was based on an early idea in Persona 5's development, where the Phantom Thieves were partaking in a globe-trotting adventure and could have possibly visited Inaba in the process. Another theory raised was
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