On a delightful weekend, Shin-chan (voiced by Akiko Yajima) and his dad, Hiroshi (voiced by Keiji Fujiwara), excitedly attend a sci-fi movie featuring robots. After the movie, the father and son enthusiastically engage in a game pretending to be merging robots, but unfortunately, Hiroshi ends up injuring his back. Unable to withstand his wife’s persistent complaints, Hiroshi attempts to seek medical attention at the hospital. However, they discover that the hospital is closed for the weekend. Forced to take a break, they find themselves resting in the park, only to be shooed away by a group of overbearing mothers.

As they journey back home, the charismatic Hiroshi is enticed by a charming attendant from a massage parlor. Sending Shin-chan home, he follows the intriguing woman into the establishment. When Hiroshi regains consciousness from a daze, he rushes home at breakneck speed, startling his entire family, as it turns out he had been transformed into a robot by the beauty salon. After the initial shock and fear subside, the Nohara family gradually adapts to their new, all-capable robot dad.

However, as more and more robot dads begin appearing throughout the city, an underlying crisis quietly emerges…