A game can be too Japanese for these reasons:
1)Nothing is explained properly.
2)Too much hand holding, making me believe that the developers don't trust us to use our brains to grasp even the simplest of things
1)I'll give you an example from Tales of Symphonia: Bad guys destroy a town. You have a chance to rebuild it by donating to the villagers. However, you need to donate exact amounts of money or the town won't be repaired. Like, first donate 10, then 7, then 23, after that, 45, then 7 etc. in correct order. The problem with this is, that I had no idea of this, because the game didn't explain me that this is how you build a town. I just assumed that if you keep donating, it will eventually be rebuilt. But no, you have to be psychic to know about how much villagers need money at what points.
Another example story wise: Half-elves are hated in the game's world. So a couple of half-elves tell everyone that they're elves, so that the community they live in would accept them. So, apparently elves and half-elves look more or less the same. But, why exactly are half-elves so hated? Is it because they're not humans? I don't remember elves suffering from this kind of persecution. Maybe I've just forgotten some lore point that explains all this, but I don't remember the game ever explaining WHAT an elf or a half-elf even is? What are their similarities? Their differences? Can half-elves breed? Are there quarte-elves? How are they different?
2)Example from Golden Sun: If you haven't played it, the game has long dialogue scenes that revolve around very simple things. And did I mention that they're long? And boring? I don't mind long scenes telling a story, if they way they tell it is interesting, just put some effort into it. Overall I like the game, it just has a problem of telling the story properly.