Together the self-proclaimed "man of all men", Riki and his quiet but alert little sister Mami must protect the Manstar Vortex from the evil influence of the SF Cosmo gang. The Cosmo Gang has been smuggling expensive space fruits to finance its maniacally galaxy-stomping campaign. Suited up to the Bangai-O, Riki and Mami must pluck space fruit from the trees to fund their own hi tech military operation and crush the evil horders.