I was bored and started to look through all of the Personas used by the main cast and realized that Naoto is literally one of the only Persona users whose Persona does not match their official gender. Like, every girl Persona user has a female Persona based off a female historical figure or goddess and the opposite for the boy Persona users.
However, both of Naoto's Persona break from this pattern. Both Sukuna-Hikona and Yamato-Takeru are referred to as males.
The only other character, and I do mean the only other character, to have a Persona of a different official gender to them is Ken Amada of all people, having Nemesis and Kala-Nemi (who is actually split between being a god or goddess in Hindu lore [or whatever the actual term for god/goddess is in Hindu I could be wrong and they are completely different people])
Now, I'm not going to say that this means Naoto is a trans man...but he does have two male warrior figures as personifications of his psyche to use in combat in a series that has always tied that to a character's gender. As for Ken...maybe they need to look into that a bit more.