Ugh, I'm going to talk about anime. MY APOLOGIES.
I was talking to a friend about character-driven stories. And, I think there are two main differentiating components: the first is 2D v. 3D 'fullness', and the second element is maturity of the characters. You can have one and not the other, but they are neither supplementary nor complementary. I have seen stories that only got the character 'fullness' right, but still had a good story. And I've seen stories that got the 'maturity' right, but I wouldn't consider their characters to be 'full'.
Maria-sama Ga Miteru would be an example of an anime that I would say the maturity outmatched the 'fullness'. The characters are...simple...at least in the sense of the sort of things that this show is concerned about. Seriously, dear lord, I wouldn't be surprised if there was an episode about "The Horror of the Tea Kettle That Wouldn't Heat Up!" And they would devolve into
ridiculous and
inane banter about the first world problem of their tea not being properly heated.
You think I'm exaggerating. Watch the show and tell me I'm exaggerating. If anything I think I'm understating it.
Either way, the kind of trivializing details that they deal with makes the characters highly unbelievable to myself. However, the protagonist does
definitely grow (not physically, of course). There wasn't one point in the series where you could point at, where the character gives some dramatic speech like in most 2D characterizations found in some animes, and then they're all of sudden a 'better person'. This was a tad more realistic, and you could see, over time, that she had mellowed and became quite the lady. Maison Ikkoku did a great job of this as well. In order to do something like that, you need to have--and Maria-sama did have--great characterization. It was a character-driven story and the maturation element was done superbly (even if I do still think the characters at any one instance were somewhat flat).
Fruits Basket I would characterize in the opposite way. I wouldn't say that their characters were more 'full' than Maria-sama (because the maturation does make characters more 'full'), but the 'fullness' of their characters was much more than the 'maturation' of their characters. Mainly because characters matured when Tohru would play her junior psychoanalyst role for the episode and change one of the other characters in the course of a single episode. This is what I mean by the maturation being 'unrealistic'. However, the loving character of Tohru did, I think, make her 'more full'.
If this makes any sense...