Do you remember Five for Fighting?
Yeah, that's them. They make it into today's post because below, I give you five cards originally created for fighting. Menko is a game similar to Pogs, where the players throw their menko cards at their opponents' to get them to flip over. Other games are found on menko cards - janken, which is rock-paper-scissors, numbers which can be used for math-based or other number games, playing card suits and numbers, and quizzes are all pretty common. As a side note, a lot of game terminology in Japan has its origins in fighting or war.
Finally, we go back to 1947 for JDM11: Card Number in Circle. I would guess that this is the earliest sequentially numbered baseball card set issued in Japan. Other card sets may have unique numbers, but those aren't sequential; Karuta cards come close, being "numbered" using the Japanese alphabet. Card 2 is Hiroshi Oshita. The first 10 cards are professional players while the last 8-10 cards (#12 and #20 aren't known) are university players.
There you have it! Five cool die-cut menko cards from nearly 70 years ago!