Although I'm pretty sure Christianity is very uncommon in Japan, and it would be unlikely to see so many crosses in a Japanese cemetary.
Well, while we're drawing on the image, I'll throw together another possibility I see and post it.
edit: Well, here ae several things I see in the image. I'm not sure if any of them are right, nor whether they all go together. Some of them seem like the object I see by themself but don't fit the surroundings, like the hand (where the heck would it be coming from?)

IMO, the simplest, fastest, and best way to find out what this is will be to post it on 4chan every few days until someone there guesses what it is. I've solved complicated questions I couldn't figure out through Google in minutes using 4chan :P