Hi Chris, This is a Japanese vase. I'm afraid I can't help you much with this as I am specialized on Chinese antiques. However, I speak Japanese.
The mark reads "Tokushu Kenrei" in Japanese, but I am not sure what it stands for. "Tokushu" would normally mean annotation, remark, comment, in Japanese. The rest means peak or summit.
This looks rather like a sort of quality assurance stamp.
