BBM doesn't just make cards. Their name is "Baseball Card Magazine" after all. They are responsible for the now-defunct SCM, several magazine specials a year, and Weekly Baseball (週刊ベースボール, Shuukan Baseball).
The first issue of Weekly Baseball had a cover date of April 16, 1958, though it was released in March. It actually was a rebranding of Baseball Magazine (ベースボールマガジン), which was first released in April 1946. The company Baseball Magazine gets its name from this periodical. Weekly Baseball passed the 3000-issue milestone back in 2010.
Bonus fact: in 2015, BBM bought the naming rights to a baseball stadium in Niigata Prefecture for 1 million yen per year (about $10,000/year).
In August of 2011, BBM reprinted the first issue of Weekly Baseball. The magazine was included in this box:
The first subset is 2011 Big Hope Rookies, featuring the top rookies of, well, 2011. Yuki Saitoh was probably the biggest name then, but Yudai Ohno also makes an appearance in this series.
I didn't know about the existence of this set until NPB Card Guy came across it and asked me to find one for him. I was able to get another for myself soon after! I've had this for a few months, but I'm just now getting around to posting it.
As always, I must wonder how many other sets are out there which remain uncatalogued.
Until next time...