Capcom has taken Koei Tecmo to court in Japan in relation to patent infringement and is seeking a settlement of $9.43 million. The first oral arguments were heard today in Osaka District Court.

The first patent named in the lawsuit was filed by Capcom in 2002 and relates to "a function that lets you acquire new content by combining an existing game with another piece of software." Capcom has listed 50 Koei Tecmo titles that infringe on this patent alone. While the details are still unclear, it would appear that this patent relates to expansion packs or DLC of some kind.

The second patent is related to controller vibration due to the proximity of foes.

Capcom is claiming that Koei Tecmo has profited around $93 million by infringing these patents, and is trying to gain a licensing fee of between 5 and 10 percent. It is also looking to force a withdrawal of certain Koei Tecmo titles — presumably some of these will be for Nintendo formats.

Koei Tecmo's Dynasty Warriors series is cited as one of the series which infringes Capcom's patent. The company has recently worked with Nintendo to produce Hyrule Warriors, a Zelda-themed spin-off which uses the core framework of the Dynasty Warriors game engine.