In addition to very occasional baseball cards, I sometimes find other souvenirs, like this box I picked up from Hobby Off, located between Yodobashi Camera and the JR train station.
Kokubo got his start with the Hawks back when they were owned by Daiei. He was basically given to the Yomiuri Giants after the 2003 season, where he played for three years before re-signing with the Hawks in 2007. Since 2013 he has been the manager of the Japan National Team.
The pin set reflects the three jerseys he wore - first with the Daiei Hawks, then Yomiuri Giants, and finally the Softbank Hawks. One other pin has the Hiroki Kokubo logo. Yes, he has a logo.
The back of the pin box just has basic retail information, including the original price - 3500 yen (about $35). I paid about ten percent of that, which especially in Japan is a bargain!