Himawari Nohara is the infant daughter of the Nohara family and younger sister to Shinnosuke Nohara. Her name, meaning "sunflower," was chosen from over 107,000 viewer submissions. Born on September 27, 1996, she exhibits a precocious and energetic nature. Floral sunflower patterns sometimes appear on her clothing and toys.

Despite her infancy, she displays notable intelligence and maturity, such as distinguishing real jewelry from fake and discarding imitations. Her interests include brand-name goods and shiny objects, reflecting her mother's tastes. Though nonverbal, contextual subtitles convey her thoughts and intentions. She crawls at remarkable speeds and frequently interacts with the family dog, Shiro, treating him as a plaything.

Her personality blends cheerful curiosity with stubbornness. She forms strong attachments, especially to favorite plush toys, and shows frustration if they are damaged. Generally amiable, she possesses a formidable temper when provoked, typically forgetting these outbursts afterward. Like her brother, she dislikes onions and often refuses to eat them.

In the film "Arashi o Yobu Appare! Sengoku Daikassen," she participates in the shared family dream initiating the story, witnessing a distressed woman by a lake. The next day, she observes Shiro digging in the garden but does not join the time-travel event. Her parents include her in their concerns and plans when Shinnosuke vanishes into the past.

The special episode "Super-Dimension! The Storm Called My Bride" depicts an alternate version of Himawari at approximately age 20, working as a police officer. This future iteration retains her childhood habit of making distinctive facial expressions upon encountering attractive men.