Congrats on your toad, can find some information about the toads natural habitat in here: AmphibiaWeb - Bufo japonicus. Also, here is our basic ground toad care article: Frog Forum - Toad Basics - Keeping ground-dwelling Toads. A care sheet for Bufo, Anaxyrus, Spea, Scaphiopus, Ollotis, Alytes, Pelobates. Good luck !