Paku is an adult alien spider from Planet Insecturu. Sent to Earth by Haru alongside his cousin Nana, his mission is to capture a human to build a machine for the Insects' planned conquest. Their target is Minako Fujitomo, a 13-year-old human genius. Despite Minako's repeated refusals to accompany them back to Insecturu, Paku persistently assists her with various problems, often making his help conditional on her eventual cooperation but frequently aiding her regardless. Paku exhibits a cheerful and quick-witted personality, frequently employing trickery to offload tasks onto Minako's robot assistant, Zamga. Though an adult, Minako occasionally treats him like a child. His relationship with Nana is defined by their shared mission and familial bond; Nana, one day younger, harbors envy towards him. Paku's background revolves entirely around this Earth mission, focusing on the dynamic between his initial objective, his persistent assistance to Minako, and his reliance on manipulation to navigate challenges.