Calbee has been including prize redemption cards since their first baseball set back in 1973. Originally called homerun cards, and now called lucky cards, these could be exchanged for various gifts. They've offered card albums, baseballs, towels, books, and, yes, even cards.
From 1990-1993, you could get your hands on an oversized card set. There were two unique series in 1990, but only one type for the remaining years.
1992 is definitely the rarest of the issues, and I'm not sure I've ever seen one in a shop. I finally bit the bullet and bought this Tatsunori Hara:
While we're at it, here are the other sets at a glance: