Michinori Tsubouchi began his career in 1936 - the first year of professional Japanese baseball - and he retired after the 1951 season. In the early years Japan had split seasons - spring and fall. During the split seasons Tsubouchi played for Dai Tokyo and the Tokyo Lions (with whom he remained after they switched to a single baseball seasons each year). He spent the early 1940s playing for Asai, and then played for the Stars and Dragons in the late 40s.
He was a contact hitter and a speedy leadoff-style batter. He struck out just 299 times in his career (in 6301 plate appearances), against 546 walks. While speed was his game, power was not. He had only a single season in which he made it into double-digits in home runs (barely: he hit 10) and hit an average of only two per year. On the surface his offensive statistics appear to be anemic, but early Japanese ball was a
very low offense affair. In 1941 (to pick one season from his career at random) the league as a whole had a .201 batting average, a .299 on base percentage, and a .248 slugging percentage.* There were 26000 plate appearances that year, and yet the league managed only 549 doubles, 108 triples, and 100 home runs. In that context Tsubouchi's 237/343/294 line, with 10 doubles, a triple, and two home runs, looks pretty good. He made the first best nine in 1946.
As for this card: I have only a guess as to what it is, and I'm not even sure that it's Tsubouchi. The seller that I bought it from listed it as Tsubouchi, and I've bought plenty of things from him with no problems, so I'm inclined to take his word for it. But I really don't know how he knows who it is. There is no writing on the card at all (besides the number 4 stamped on the back). You can't tell which team the player is on, and his face is hard to make out. Basically all you can tell about him is that he's wearing the number 1. My best guess is that it's a JBR 37 card, from the 1949 "Marusei Home Run Batter" set. Engel says that these cards usually,
but not always, have text specifying the team and player. Here's his description of the Tsubouchi card from this set: "RHB, knees up, #1". Not much to go on. I don't know what 'knees up' means, but he is a RHB wearing #1, and it's possible that this is one of the JBR 37 cards without text on it. That's my best guess. If anyone has any better ideas, please let me know. I also might message the seller and ask how he knows that this is Tsubouchi.
*An aside about on-base percentage and slugging percentage: it's very rare for someone to have a slugging percentage lower than their on-base percentage. Since any hit contributes to both, and any extra-base hit contributes a lot more to slugging than to on-base percentage, in order to pull this off you need to be a batter who takes lots of walks but who has no power at all. Brett Butler was the first guy that I thought of, and sure enough he pulled it off a few times, but it's pretty unusual. Tsubouchi's entire league did this. Curious to see if it's ever happened in MLB, I looked through the dead ball years, and found only one season. In 1918 the AL had an OBP of 324 and a SLG of 323. I'm pretty sure that's the only time an entire league in the US has done it. So the 1941 JPBL was like the dead ball era, except
much more extreme.