Koichi Seiyama - is a video game composer. Koichi Seiyama began his career in 2004 and has worked for companies such as Arc System Works, Sega Sammy Holdings, Arc System Works Co. and Aksys Games. Koichi Seiyama's first game was Guilty Gear X2 #Reload which was released 19 years ago. Best Game Koichi Seiyama contributed to was Guilty Gear X2 #Reload. Koichi Seiyama's latest work is Guilty Gear XX Accent Core which was released 16 years ago.