[KyleGoetz]

I have been told by Japanese that I have only a slight American accent when speaking Japanese (I've been told the same about my Chinese, but my Spanish accent is very gringo). I think you should absolutely work toward removing traces of foreign-ness in your speech patterns.

In my opinion, American-accented Japanese is hideous and sounds awful. I mean, can you imagine being friends with SOMEone WHO talks LIKE this ALL the TIME? Because that's what American-accented Japanese sounds like. Japanese is pitch-based accent, while English is stress-based accent. Americans (I imagine other native Anglophones as well? I didn't know enough over there to notice) use the stress way too much in Japanese, and it hurts to even my ears, and having learned Japanese stateside initially, I'm more used to it.

If you're ever going to do anything business-wise with the language, I'd suggest losing the accent as much as possible. When I lived in Japan, my university actually offered a class on this for foreigners.