Himawari appears as an infant. She is the younger sister of Shinnosuke Nohara. Her accidental swallowing of a small black sphere ignites the central conflict. This sphere possesses significant power and is a key component needed to revive the powerful evil entity, Jarke. Her inadvertent ingestion places her in immediate danger, making her the target of the antagonistic Tamayomi clan who seek the sphere to achieve world conquest. Consequently, her family, the Noharas, are forced into a protective role. They must flee with allies to prevent the sphere's extraction and safeguard Himawari from the pursuing forces. Her infant vulnerability necessitates this external protection throughout the ensuing chase and conflict. The pursuit spans locations from Tokyo to Aomori at the northern end of Japan's main island. Her condition remains a persistent focus for the protagonists protecting her and the antagonists aiming to capture her. Resolving the conflict inherently involves her safety and the fate of the sphere she swallowed.