How do you get the breeding garden on sonic adventure battle 2

There is no breeding garden. Go to the black market in the chao kindergarten(the lockers) and if you went at the right time there will be heart fruits for 300 coins. Buy 2 and give one to the each of the chaos. They should grow a ring of flowers around them. If one doesn't, pet the chao and stuff an put it next to the other chao. Hope this helps