Using an Australian iPad Air in Japan on NTT Docomo

Hey guys,

I'm probably going to end up buying an iPad Air soon. However, I'm currently not sure whether I should get a Wi-Fi model or a Wi-Fi + Cellular model. I'm going to be spending a year in Japan in 2015, and whether or not it will work on Japanese carrier NTT Docomo is essential for my decision.

Does anyone know whether it'll work?