It's in the year of 2001. Five young persons are called up for GAO RANGERS by a shaman who knows the intention of "Power Animals". Those five young persons were making very ordinary living until that time; however, they have intuition to feel Mother Nature and outstanding motor never just like wild animals.

On top of it, they are second to nobody in loving Nature and Human lives. The reason they are called up is to protect the earth from a wicked group called 'Org'. They are possessed of the powers of "Power Animals" namely Lion, Eagle, Shark, Bison and Tiger. They put on the masks and suits of those animals, and transform themselves into respective animals. Moreover, when their minds become one, they can combine into a gigantic robot and get rid of the members of 'Org' one by one.