Both of these cards feature important pre-war Hall of Famers - Minoru Yamashita on the left, Kenjiro Matsuki on the right. Nick, who has a really excellent player collection of Japanese Hall of Famers that he has detailed his collecting of here, commented on my earlier post that the toughest hurdle for anyone trying to pursue such a collection is guys whose playing careers were entirely before the War. For guys who started their careers before the war, then resumed them in the late 1940s (like Tadashi Wakabayashi) its not too hard to find cards of them since they appeared in menko sets from the late 40s and early 50s which, while not plentiful, can still be found.
With the exclusively pre-war guys though it becomes a big headache. Famously Eiji Sawamura, Japan's most beloved pitcher from the early days and for whom NPB's version of the Cy Young Award is named, has no known surviving cards from his playing days (which were entirely before the War in which he died). But even for the guys who have known cards they only exist in sets where maybe 4 or 5 copies of each card survive.
None of the sets from the 1930s survive in any quantity today, so there is a huge bottleneck in terms of supply of cards of players who only played in that decade (or before). I'm not sure why that is. One explanation is that there simply weren't too many of them produced to begin with. Cardboard menko were still relatively new back then and maybe they just didn't catch on much with kids. Notable support for this explanation is to be found in the fact that there aren't any known sets from the mid to late 1930s, all of the known ones seem to have been made between 1929 and 1931, then there is a huge gap until after the War. If the kids didn't buy them, then they wouldn't have made too many and given up on the idea.
A second possibility is that lots of them were made, but most were destroyed during the firebombing of Japanese cities. This explanation suffers from a couple of problems though. One is that Japan wasn't anywhere near as urbanized in the 1940s as it is now, so most of the population back then lived in the countryside or smaller towns that weren't bombed. So if the cards were roughly evenly distributed around the country according to where people lived, then only a fraction of them would have been destroyed in the bombing, unless they had only been distributed in major cities (which is possible, but not certain). Another problem is that this explanation doesn't explain why only cards from prior to 1931 survive.
A third possibility is that a lot of cards were made, and few were destroyed by the bombing, but most were recycled. During the War the government organized major recycling drives to suck up all the resources they could for the war effort. This mainly focused on metal, but also included paper and cardboard. Perhaps they were all turned into carboard boxes or something. A problem with this explanation though is that lots of other things made of cardboard and paper (like books and postcards) survive from that era, so the recycling programs don't seem to have gobbled up too much (and menko are so small they likely wouldn' t have bothered).
A fourth possibility is the American one - everyone's mom just threw them out!
A fifth possibility is that the government may have actively suppressed baseball menko specifically. The main piece of evidence supporting this is the fact that the gap that exists in the baseball card archeological record between 1931 and 1947 is not replicated in the Sumo card record. This can be seen from the many examples of sumo menko sets from that time frame that SumoMenkoMan has recorded. The gap in baseball menko notably coincides with the rise of nationalist fascism in Japan and the deterioration of its relations with the US which led to the war. Being associated with America, the government may have discouraged the production of baseball menko while encouraging (or at least allowing) the production of sumo menko since that was a Japanese invention.
A sixth possibility is that all five of these are correct to varying degrees and each of these factors contributed to the paucity of pre war cards. I think this is the most likely explanation.
Anyway, the reason I bring this up is because one of these guys, Yamashita (above), had an exclusively pre-war playing career. He was a star with Keio University in the Big Six league, where he led the league in batting average in 1929. This card features him during his Keio days so probably dates to around then. He played against both of the Major League All Star teams in 1931 and 1934, then joined the newly formed Hankyu team for the 1936 season. He hit the first home run in Japanese professional baseball history that cleared an outfield fence in his first year. He played with Hankyu until 1940, then played a single season with Nagoya in 1942, his last as a player. He worked as an umpire after the War and was elected to the Hall of Fame in 1987.
Yamashita only appears in a handful of extremely rare pre-war sets (JRM 43, JCM 46, JCM 60, JCM 144) all of which have a rarity factor of R4 or R5 (meaning fewer than 5 or 10 copies of each are known to exist) so he is one of the hardest hall of famers to land a card of.
The other card features Kenjiro Matsuki, who was also a university star who went on to play in the newly formed pro league from 1936. His professional playing career with the Tigers was almost entirely pre-war, but he did very briefly appear in the 1950 and 1951 seasons (11 games combined between the two). He doesn't appear in most of the post-war sets except one: the 1950 JCM 21 Babe Ruth set, which is a lucky break for Japanese Hall of Fame collectors. This set is designed like playing cards and gets its name from the fact that it has a Babe Ruth card in it. Its actually one of the easier to find sets from that era, with a sizeable number still existing as uncut sheets, so most people who want a Matsuki card can get one from that set without too much difficulty. He also appears in some (though not all) of the same extremely rare pre-war sets that Yamashita does.
This card of mine is really interesting as its actually an error card. The kanji on the left definitely say "Matsuki" (松木）and the player image is definitely him (he was one of the first Japanese players to strike that signature look with glasses). But the kanji on the right (早大) denotes Waseda University. Likewise the lettering on his uniform is a bit hard to read but seems consistent with "Waseda".
The problem is though that Matsuki never played for Waseda. He went to school at rival Meiji University and played for them in the Big Six league.
So that is kind of neat!
Given the similarity in art style, size, players depicted and inks used I would say these are both from the same set, which is not yet catalogued and thus these seem to be the only known copies of each. They are a pretty big addition to my collection even though I'm not actively working on a Hall of Famer player collection.