Chako, the secondary antagonist, orchestrates a scheme with partner Ken to resurrect the nostalgic allure of the 20th century, driven by mutual contempt for the 21st century’s “smell.” Together, they construct the 20th Century Expo and an adjacent village to imprison adults in perpetual twilight, intensifying their yearning for bygone eras. Her poised, reserved demeanor contrasts with a sharp-edged elegance, clad in a black long-sleeved top, miniskirt, and white belt, her expressions rarely betraying emotion.

While enforcing the couple’s agenda with calculated ruthlessness—rebuking subordinates for failing to subdue Hiroshi—she reveals fleeting humanity. During the Nohara family’s visit to Ken’s apartment, she serves tea, sews on an antique machine, and tenderly feeds Shiro milk, her actions laced with understated warmth. Her motivations align with Ken’s, whose devotion to reviving the past appears rooted in fulfilling her undisclosed desires.

The plan crumbles as citizens reject nostalgic entrapment, exposing her fragility. Defeated, she and Ken leap from a tower in a suicide pact, halted mid-fall by a pigeon shielding its nest. The sight fractures her composure, unleashing tears and a confession of mortal fear. Their fate remains uncertain, hinted to involve relocation and rebuilding.

Beyond the central narrative, Chako briefly surfaces in *Crayon Shin-chan: Invasion!! Alien Shiriri* but is absent from flashbacks in entries such as *Crayon Shin-chan: Fierceness That Invites Storm! Me and the Space Princess*. Her aesthetic inspired Jacqueline Feeney in *Crayon Shin-chan: The Legend Called: Dance! Amigo!*. No spin-offs, OVAs, or televised seasons expand her backstory or role beyond these instances.