As Pion, revealed to be a robot who the heroine now calls P-ko, joins the party, they encounter her companion Oyage, a similar robot who calls himself O-taro, who wants to abandon his mission and live in the strange city. As he sends a killer digger truck after them, they all fall down a hole, winding up at an underground castle. The heroine and assistant are confronted by O-taro, who combines with the slimes to become a "Killer Death Cat", though the fairies step in to help them. With help from the fairies, P-ko manages to defeat O-taro using a super-powered microwave, which in turn restores their memories. After the gang manages to escape the city, it is revealed P-ko and O-taro, whose real names are Pioneer and Voyager, were deep space probes that gained humanoid form. O-taro makes P-ko realize that deep inside, like himself, she does not want to leave the warmth of the solar system. Hearing these thoughts, the heroine sabotages the electric generator, stopping P-ko and O-taro from being able to leave before reworking them to become wind-up powered.