Piguko is a young female Pigmon character with pink coloration, frequently depicted carrying a balloon—a visual nod to the original Pigmon design within the Ultraman franchise. She forges a deep bond with Midori soon after their first meeting in "Ultraman Kids: The Pleasant Friends of Planet M7.8", a friendship central to her narrative. When Midori must depart Planet M7.8 alongside Gamarra and Majara, Piguko becomes visibly distressed by the separation, highlighting the strength of their connection. This situation resolves as Midori chooses to stay on Planet M7.8, resulting in a joyful reunion between the two. A recurring sign of their close companionship is Midori often perching atop Piguko's head during shared scenes. Notably, the television version of Ultraman Kids portrays the character named Piguko as male, presenting a distinct interpretation separate from the pink, balloon-carrying female version featured in "The Pleasant Friends of Planet M7.8".