While the boy is in danger, Kouchu saves a boy from snakes after he plays with them. After, the brawlers are given devices called "CrystalDex". So Kouchu saved him and the boy thanked him. So the brawlers were able to use their CrystalDex to search for Crystal Monsters. The CrystalDex is special to the brawlers also, so they could use it to detect any Crystal Monsters while they are traveling as Crystal Brawlers.