Midori Yoshinaga is Shin-chan's mother and a core member of the Nohara family. She is thrust into action protecting her infant daughter, Himawari, after Himawari accidentally swallows a mystical orb coveted by two clashing clans. This artifact holds the power to revive an ancient evil. Midori joins her family's desperate cross-country escape from the Tamayomi clan, who pursue the orb to achieve their goal of world conquest. Her efforts form part of a collective struggle alongside her family, three brothers from the rival Tamayura clan, and female detective Yone Higashimatsuyama. Their journey across Tokyo and Aomori focuses on safeguarding Himawari and preventing the orb's misuse.