CollectingJapaneseMenko

JCM 141: 1962 War/Playing Card Back is a short set of 8 cards, measuring 1 5/8" x 2 5/8". As with other playing card backs, it matters for the arrangement - this one has a horizontal card on top, and a war-themed image beneath, along with a massive menko number. The backs seem to be unrelated to the fronts.

JCM 139: 1962 Marukami Cartoon is a fun set, different from other JCMs from this period. It is a bit smaller, at 1 3/16" x 2 7/16", and there are 20 in the set.

JCM 137: c.1960 Maruten Question Mark Back is a set of 40 cards. These have a very busy back, including the team name, a question mark, a menko number, etc. While the menko numbers are duplicated, they are unique to the front side at least.

JCM 136: 1959 Maruten Blue Pitching Back continues the pitching back line with blue colors, but sadly the backs are not unique to the fronts.

JCM 135: 1959 Maruten Sequential Black and White Blue Pitching Back is a unique set with almost 100 cards in it. This series features a dozen players, with a sequence of around 10 cards that provide a "flip book" of sorts of an action shot. Cards are numbered on the front for what part of the sequence they are part of.

JCM 134: 1958 Black and White Space Fantasy is another fun set, with at least 22 cards in it, featuring fatasy cartoon characters on the back with unique menko numbers. I've included a few here that haven't been catalogued yet.