If I'm reading the date correctly, this Japanese coin should be Year 44 (1911) 20 Sen - and a pretty good date with a mintage of 500k. Am I correct?
Yes, "明治四十四年" is Meiji Year 44, or 1911, but this will display backwards on the coin because it dates to when Japanese was written right to left. And yes, the JNDA catalog (the annual Association of Japanese Dealer catalog, published all in Japanese) shows that particular year as having a mintage of 500,000 and fairly valuable in high grades. Looks like a decent find.