Honoka Kurosaki is a middle school student who lives in Takasaki City within Gunma Prefecture. She is fourteen years old and in her third year of middle school, placing her one grade above Kokona Aoba. Physically, she stands 153 centimeters tall and has short black hair, often favoring a boyish style of dress that can lead to initial confusion about her gender. Her family includes an older brother named Taiki Kurosaki, for whom she shows a noticeable, affectionate attachment.

Her personality is defined by a quiet and reserved nature, as she seldom displays her emotions openly and is not particularly adept at socializing. This initial shyness and tendency to be a person of few words contrasts sharply with the more outgoing personalities of the main hiking group. However, this reserved demeanor softens over time as she grows more comfortable within the group, and she is capable of forming deep connections with those who share similar character traits. Her motivation to spend time outdoors is deeply tied to her passion for landscape photography, a hobby that defines much of her approach to the world; she is frequently seen carrying a camera to capture the natural scenes on her hikes.

Honoka first appears during a climb up Mount Tanigawa, where she meets Aoi Yukimura on the trail. This encounter marks the beginning of her integration into the main cast. Her role in the story expands significantly by the third season, where she joins the group on a trip to Lockheart Castle in Gunma to document their experiences with her camera. Her presence serves as a narrative parallel to the central friendship between Aoi and Hinata, showcasing how mountaineering can foster connections between individuals of different personality types, particularly as she is a character navigating the social and personal growth of adolescence.

Her key relationships are central to her development. She shares a meaningful friendship with Kokona Aoba, who is closer to her in age and openly expresses admiration for Honoka's photography. This bond deepens on a Valentine's Day hike to Mount Mitake, where it is revealed that a photograph Honoka took of Kokona at Lockheart Castle emitted a sense of palpable warmth, strengthening her desire to know Kokona better. Kokona reciprocates this admiration, and their growing closeness is symbolized by them holding hands while passing through a tree trunk at a "power spot" for relationship luck. Honoka also forms a significant bond with Aoi Yukimura, who first spoke to her on the mountain; Aoi recognizes a kindred spirit in Honoka, and they maintain their connection through email and further climbing trips. Her relationship with Hikari Onozuka is notable for a misunderstanding, wherein Hikari mistakenly assumes Honoka is Aoi's girlfriend due to her boyish appearance and their closeness.

Throughout the series, Honoka demonstrates notable development. While initially only joining outings when accompanied by Kokona, her reserved nature lessens as she becomes more proactive in group interactions, even accepting invitations to hike without her closer friend. Her observational skills allow her to perceive the depth of Aoi and Hinata's friendship when she overhears them discussing a disagreement. In the events following the third season, she participates in a snowshoeing trip to Mount Akagi, embracing the experience even when unseasonably warm weather melts most of the snow, which underscores her prioritization of camaraderie and new experiences over perfect conditions. Her signature ability is her skill in photography, through which she expresses her appreciation for nature and creates images noted for their warmth, particularly those featuring her friends.