To be honest, picture size is so large I kinda had to run back and forth to get a look at the rifle (opposite of what we usually see- a postage stamp sized pic taken in bad light with a cell phone camera!
However, I am fairly sure you have an Arisaka, type 99. If so, here is some info on decyphering markings. Markings on Japanese Arisaka Rifles and Bayonets of World War II
If you want to try shooting it, PLEASE have a competent riflesmith go over the rifle first- some of the rifles made at the very end of the war are simply not safe to shoot using anything- but when we were not bombing the hell out of Japan, the Arisaka was a well made, very strong action.
Anyone else? Anyone? Bueller? Anyone?
PS- welcome to the forum- when you get a minute, please stop over in the intro section, and say howdedoo.