In the comments to my tribute to Koichi Hori post the other day, Deanna and I have been discussing guys who spent their entire career with a single team, especially ones with 20+ year careers. My initial thought was that this was pretty rare in the days before free agency - at least for players with teams other than the Giants. I was looking at how I could do more research on this, so I took a look at the player record section of Japan Baseball Daily's Data Warehouse just to see how hard it would be to simply brute force look at every player record. Lo and behold, in the very first section, I found a guy who had spent 20+ years with the Hankyu Braves in the days before free agency - Mitsuhiro Adachi, who pitched for them from 1959-79. Here's his card from the 2009 BBM Hanyku Memorial set (#05):
So I'm thinking now that I'm wrong and that there are more guys than I thought. I'll have to see if I can find the time to do more research.