T5J8F8 said:
you can't just search for, say, sora and expect the sora you're looking for.
This is generally true no matter which version you pick though--if a character has an ambiguous or common name, chances are there are more characters with that name.
As a counter-example for the "Japan first" thing, Winnie the Pooh shouldn't be tagged with the Japanese name Kuma no Pu.
I feel strongly that the original is just the most consistent and easy method, since there's always objectively one original name, no matter what. Then, if other versions of the name are also commonly used, they can be aliased towards it.