How do you make a Hero Chao

To create a Hero Chao, raise it using Sonic, Tails or Knuckles only and be sure to not mistreat it with these characters. When a Chao has reached its evolution stage it should become a Hero chao and unlock the Hero Garden if not unlocked already.

An alternate way is to abuse the Chao with a Dark character, Shadow, Rouge or Eggman, but this will shorten your Chao's lifespan and decrease it's chance of reincarnation.