Can't tell you what it is, until/unless I find the right book, which is buried around here somewhere.
I can tell you what it is NOT, it is NOT one of the Arisaka service rifles issued to Japanese troops during WWII. It is tough to tell from the pics, but based on the position of the bolt handle, and the shape of the cocking piece, it is not a type 38 (6.5mm) or type 99 (7.7mm) that were the WWII service rifles.
It could be a dummy, or a drill rifle, or a training rifle. Possibly the pre type 38 service rifle, but can't begin to tell until I find the right reference.
It is a Japanese military rifle (the crest), but which one I cannot tell right now. Only that it is not the WWII service rifle commonly called the "Arisaka".
It might have been designed by Col Arisaka, and if it was, then technically it is an Arisaka, but it isn't one of the ones we usually see. I have a few of those, and that rifle isn't it.
I'll keep looking, and if I find any info, will let you know.
Can you estimate the caliber (bore size)?