BBM has been issuing team sets under the "Legends" name since 2013. Hiroshima is the most recent team to receive the treatment.
The Legends series is nice in its simplicity, and the player selection focuses on certain eras usually during dynasties. This has the opportunity to provide a bit of a different player selection from the usual anniversary sets. There are still plenty of retired players which have no modern cardboard and are in the record books for winning awards or other accomplishments. But like most of BBM's team sets, there isn't really anything special here for collectors who aren't fans of the respective teams.
I like the red and green colors used in the base set; other sets have used more muted tones in blues or grays. I've missed posting about at least one set - the Giants - from this series.
You can see more scans and read a bit more about the set at Japanese Baseball Cards, which NPB Card Guy wrote about a couple months ago... somehow this set slipped through the cracks.