Is this version the same as the original Persona 5 that released on the PS4?

[Mateo | XlV]

Just an upgrade like Final Fantasy 15?
Will it introduce every character or is this like an expansion?

[kgfzrt]

It has extra content and QoL Features, so nope, not the same, but it is the same story, for the most part

[Gabby]

This is the "True Version", a thing that's happened in the Persona series since 3. (FES, Golden, now Royal).

Each one tends to add a new character into the mix and extends the story by 3-4 months of time, pushing the story past the previous ending. It's the original game + an expansion all mixed into one.