@sorg I thought they were pretty straightforward in SMT3 personally, but I found the story being needlessly spread out (a trait which is common in SMT games I later found out)! Sometimes with so little to go on in order to encounter the next bit of it.
SMT characters are usually far more interesting as they have complicated reasons (most times) for their actions. I love that for SMT games in general. SMT5 was pretty good until the last dungeon, when I simply noped out, excited for Vengeance!