Ring Snowstorm is a Time Patrol officer from the 30th century's Asian branch, tasked with monitoring history and preventing temporal crimes. She pilots the patrol boat P23-27X and employs specialized "Dona suits," powered armor multiplying the wearer's defensive capabilities and physical strength twentyfold. While investigating temporal abnormalities in Japan's Warring States period (1570 AD), mysterious spacetime torpedoes crippled her vessel during transit. This forced an emergency landing deep underground beneath the Nohara family's backyard in modern-day Kasukabe, directly under their dog Shiro's kennel. The crash disabled her time machine, trapping her. With communication systems damaged and headquarters contact impossible, she initiated contact by temporarily possessing Shiro's body. Speaking through the dog, she informed the Nohara family of the disrupted timeline and requested their assistance, as her own resources were insufficient. To enable their journey, she provided Hiroshi, Misae, and Shinnosuke with field jersey dresses, or time suits, for safe temporal travel, along with a disposable emergency three-seater spherical time machine. The family agreed to help, spurred by Shinnosuke's insistence and the theft of Misae's bag containing important documents by minions of Unkokusai. Ring Snowstorm monitored their mission from her stranded position. After the Nohara family helped defeat the antagonist Unkokusai (Hieru-Jokoman, "Stinkpoop"), resolving the Warring States crisis, she expressed deep gratitude. She then returned to her original time in the future. Her name translates to "round snowstorm" in specific Chinese characters. This character appears exclusively within this particular film narrative.