Nadeshiko Kagamihara is a first-year high school student who moves from Hamamatsu in Shizuoka Prefecture to the town of Minobu in Yamanashi Prefecture and enrolls at Motosu High School. Her initial encounter with camping happens by chance when she falls asleep while cycling to see Mount Fuji at Lake Motosu and is found by Rin Shima, who shares a cup of ramen with her. This experience sparks Nadeshiko's deep enthusiasm for the outdoors. She is characterized by her high energy, cheerful disposition, and a noticeably large appetite. She often acts impulsively and can be forgetful or naive, which occasionally leads to minor mishaps. Despite this, she is genuinely warm-hearted and eager to help others.

Her primary motivations are experiencing nature, sharing meals with friends, and improving her camping skills. To afford camping gear, she takes on part-time jobs, such as delivering New Year’s cards and waitressing. Nadeshiko possesses remarkable physical stamina, a result of a summer training regimen her older sister, Sakura, imposed during her middle-school years to help her lose weight, which involved cycling long distances around Lake Hamana. This background also explains her slim figure despite her constant eating.

Within the story, Nadeshiko serves as the central figure who brings the group together. She joins the Outdoor Activities Club at school, where she becomes close friends with Chiaki Ogaki and Aoi Inuyama. Her most significant relationship is with Rin Shima; their friendship deepens over time as Nadeshiko’s extroverted nature gently encourages Rin, who prefers solo camping, to participate in group activities. Nadeshiko respects Rin’s need for solitude while persistently inviting her to share experiences. She also has a caring but slightly teasing bond with her older sister, Sakura, who often looks out for her.

Nadeshiko undergoes clear development over the series. She starts as a complete novice who dives into camping without much planning but gradually becomes more knowledgeable and responsible. By the second season, she successfully undertakes her first solo camping trip, demonstrating her growth. She also becomes more attentive to her friends’ needs.

Notable abilities include her cooking skill, especially hotpot dishes, for which she earns the nickname Nabeshiko among her friends. She is a quick learner when it comes to campsite setup and outdoor techniques. By the time of the film, she has obtained a driver’s license and a certificate for operating heavy machinery, which aids in a campsite regeneration project.