Menko Stadium is a Japanese collectible card game published by Konami in October 2001. It takes its name from menko, an ancient Japanese card game dating to the Edo period in which players toss thick cardboard pieces to flip opponents' cards using force or wind. Konami adapted this traditional format into a modern CCG release, using characters drawn from across their own software catalog: Metal Gear Solid, Silent Hill, Tokimeki Memorial, and Suikoden characters all appear in the known card pool. The result is a cross-franchise showcase product as much as a standalone game. Cards from the series are now sought by collectors interested in vintage Konami franchise memorabilia, particularly the Silent Hill and Metal Gear Solid representations. Detailed gameplay rules and the full extent of the card pool have not been widely documented.
Source: shshatteredmemories.com/collection/portfolio/konami-silent-hill-menko-stadium-cards-jpn/