Chao Adventure is the VMU mini-game for the Dreamcast. This mini-game is designed to train your Chao to become faster and stronger, so it can then be used in Sonic Adventure and Sonic Adventure 2. The game appears when you transfer a Chao from the Chao Garden in Sonic Adventure to the VMU. When Sonic Adventure 1 and 2 were re-made on the GameCube, Chao Adventure was replaced by the Tiny Chao Garden in the Sonic Advance Series.
In the game, the Chao goes on an "Adventure Walk" where skills are improved, depending upon the selected course. Along the way, the Chao may find fruit in treasure chests, encounter bullies and meet characters such as Sonic, Tails, Knuckles, Amy, E-102 Gamma and Big.
By connecting two VMU units together, two Chao can be bred.