Japanese WWII Ammo Pouch

Japanese WWII Ammo Pouch-This is an interesting item, it is a Japanese ammo pouch which is later war, as it was made out of a rubberized material, that has since stiffened up to almost a plastic material. This pouch was originally used for Arisaka rifle ammunition. There is also a number 4 with what I believe to be the word Saishi under the lid which has been written in a white paint. An interesting pouch with what could be an interesting story behind it.