Sorry to say, but the photo shows almost no distinguishing characteristics to help with identification! By that I mean flowers, cones, foliage shape and attachment, etc.
Still, I'll jump in. I think you have a gymnosperm there. The two most prevalent non-pine conifers in Japan (at least in a forestry setting) are Chamaecyparis obtusa (Hinoki false-cypress) and Cryptomeria japonica (known in Japan as "sugi" and incorrectly in the west as "Japanese cedar"). I wouldn't be suprised if it were the former. Be aware that simple "picture matching" for ID of these is a tad iffy in that there are lots of horticultural varieties out there, particularly with the former species.