Kaede Saitō, a high school student and experienced solo hiker, first meets Aoi Yukimura at a mountain gear store, offering advice on sleeping bags and sparking a friendship. She funds her mountaineering passion through part-time work, favoring practical comfort over fashion. Standing 164 cm tall with a notably attractive figure, she has long black hair, wears glasses, and is often seen in casual homewear like sports bras and shorts. Despite her hiking athleticism, she cannot swim and harbors an apprehension toward kitchen knives, complicating outdoor cooking.

Academically capable but inherently unmotivated, Kaede frequently procrastinates, requiring tutoring from friends like Yuuka Sasahara or younger companions such as Kokona Aoba. Approachable yet self-reliant, she initially prefers solitary hikes but gradually embraces group excursions, evolving into a trusted mentor for Aoi and Hinata. Her close bond with classmate Yuuka includes lighthearted conflicts over fashion, as Yuuka encourages more feminine attire while Kaede remains indifferent.

Her character development shifts from solitary pursuits to valuing communal experiences, though she declines joining formal clubs like Koharu Senjuin’s mountaineering group to maintain her personal style. In Season 3, she supports Aoi's renewed Mount Fuji summit attempt while navigating academic responsibilities and social expectations. Her interactions consistently position her as a knowledgeable yet approachable guide whose expertise and vulnerabilities deepen the group dynamic.