They really aren't that subtle about it. They take two opposing character types and mash them together. Kanji is a tough guy who beats people up, but he is also a nice guy who sews, Yukiko is a calm, dutiful girl but she is also a girl who gets very angry or likes to laugh and joke around. Teddie is a playboy who hits on all the girls but hes also very innocent and childlike. Chie likes to fight and beat stuff up but the role she wishes to be is a shield or protector to her friends. Naoto wants to be a cool mature detective but she is also very shy and childish. I would say that Yosuke and Rise are the most well realized and dynamic of the cast, showing a more subtlety and nuance to them, Yosuke especially.
I really hope you don't take it that I am just like slandering P4 or something. P4 is great, the characters are great, but I do feel that they could be more subtle about making the characters multi faceted. In Chie's case, shes even a static character, and if she wasn't likable off the bat, she would have turned out way differently. Hell, plenty of people don't like New Chie now that she has a different voice actor and characterization due to it. What was once a laid back and chill girl is now a loud and excitable and kind of rude girl. It is really interesting how tone and delivery can completely change how you perceive a character. Voice actors really do bring characters to life.