Prime Nine was Konami's flagship collectible card game for Nippon Professional Baseball, running from 2002 through 2005. It replaced the Field of 9 series that Konami had launched in 2000 and maintained a consistent card-back design across all releases. Most years saw the line split into two or three numbered series volumes, while 2004 and 2005 added distinct First Edition and Second Edition pressings. The sets incorporated premium inserts uncommon for Japanese baseball cards at the time: jersey relics appeared in the 2003 release and bat memorabilia cards were included in Special Team Edition packs during 2003 and 2004, with autographed cards also available in 2004. Cards featured NPB players rendered in Konami's Power Pro chibi art style. The game component was linked to arcade and video game tie-ins, though the precise scanning or input mechanism varied by release. Prime Nine was succeeded by the Baseball Heroes and Powerful Baseball lines after 2005.
Source: japanesebaseballcards.blogspot.com/2025/07/a-brief-history-of-npb-collectible-card_26.html