Good Question! This has been made super unclear so let’s try to clear it up. Team Ren: Ren Amamiya is the name for Joker used in the official anime. It’s also used in the Spinoff Persona 5 Dancing in The Sunlight. Team Akira: The manga based on the game uses the name Akira Kurusu. If you’re used to Japanese media, you’re probably used to treating manga as canon over anime. But since the anime and manga are both based on the game as a prime source that argument doesn’t work here. Soooo long story short. It feels like Ren outweighs Akira. It is used in more media and makes more sense. But it’s an RPG so name him whatever you like.