To play as Kumachan the bear, you must fight 50 rounds in the arcade or V.S. modes. To play as Panda Kumachan, put the cursor over Kumachan on the player select screen, and select him while holding "up".

For an easier route, start a game in Arcade Mode on the Hyper setting. When the match begins, hold A + B + C and press Start. Once you've gone back to v.s. or arcade Kumachan will be selectable.