Japanese Military Type 99 Arisaka Rifle - Toyo Kogyo Arsenal Series 31 - 7.7x58mm.
The chrysanthemum symbol was grounded off on these rifles after they were surrendered after the war however, it is still visible on this rifle. The Toyo Kogyo rifles were produced between 1939-1945. Has the anti-aircraft rear sight and an inverted "V" front sight with protective ears. No import markings.