Beautiful cards!
I believe those are from one of the 1960 or 1962 Marusho Flag Back sets (JCM 13).
The "A" penciled on the back of yours was put there by an American who imported them to the US back in the 1960s. You can read more about the interesting history behind them here:
http://japanesebaseballcards.blogspo...orters-of.html
They are worth something, especially if you have Sadaharu Oh (I can't quite make out the players in the photo).