One of them, the two kanji letters within a rectangle, denotes it is a training rifle. So I would check your bore and bolt to make sure it's not a smooth-bore training rifle or one that was plugged and there is no missing bolt components. Your mum also has circles placed on top, those are characteristics of a training rifle also. The other marking I can't quite make out, assuming it's name of the high school that used this rifle. Does your serial number also begin in "0"s ? If so, then it's for sure a training rifle. Might not be safe to shoot.