I told you. They worked differently back home.

There was one of each crest there, and they were kept for us, the Chosen Children, for safekeeping, until Piedmon stole them. He gave them to Devimon, who hid them around Server, but Myotismon somehow got mine. Taichi says he found his hidden as a cave wall, and Mimi-san got hers from inside a giant cactus.