At this point, I don't think he's accomplished enough of a hitter to say that. If he moved across right now I'd say maybe he hits 7th or 8th and then gets some pinch hitting AB's, but that's about it.
His OPS by year in Japan: .660, .842, .628, 1.004. Not to say that you shouldn't expect some early struggles from a teenager playing in a professional league, but its not like he's been a prodigious hitter during his career.
If he plays both ways, I only really see it as a DH (hasn't played OF in Japan in two years per BR), and even then that means he still has to hit considering the DH is the most premium offensive position. Definitely could be an asset as a pinch hitter in the NL though if the bat is legitimate.