Dark Matter is Pin #261 in The World Ends With You. It is a pin obtained by fighting Reaper Beat on Ultimate, Sho Minamimoto (Taboo form) on Hard, and Draco Cantus on Hard. Can also be obtained by trading in 10 Shadow Matter pins to the shop owner in Shibu-Q Heads 1st floor.
Related ThreadsDark Matter - last post by @ Aug 9, 2008
Money and Dark Matter - last post by @ May 16, 2008
Dark Matter - last post by @ Aug 6, 2008