I picked up my first Karuta card off Ebay recently. Karuta is a card game in Japan that goes back hundreds of years. There are two types of cards in a Karuta set - picture cards and reading cards. A picture card shows a picture (obviously) and a reading card contains text. Each card has a hiragana character on it - each card is paired with one of the other type by the hiragana character. (NOTE - I think I'm describing one variant of Karuta - Engel says it's "Iroha".)
The card I got is from a set from 1949 that Engel refers to as "JK2 - 1949 Karuta (Team Emblem)". It shows Makoto Kozuru of the Daiei Stars and Michio Nishizawa of the Chunichi Dragons.
I got the corresponding reading card as well (where you can see the "team emblem"):
This particular pair of cards is matched by the hiragana character "ni" which is actually shown in English on the picture card. Not all Karuta sets show the hiragana character in English.
The heyday of the Karuta sets appears to have been between 1948 and 1958. Engel lists 23 sets from this period, along with a couple from the 1970's.