"Yama no Susume" centers on Aoi Yukimura, a shy and reserved high school girl who reconnects with her childhood friend, Hinata Kuraue, after years of drifting apart. The series revolves around their shared passion for mountain climbing, a hobby they enjoyed together as children. Aoi, who has become timid and fearful of heights, is encouraged by the energetic and adventurous Hinata to rediscover her love for the outdoors. The narrative follows their journey as they tackle various mountains, starting with small local hikes and gradually progressing to more challenging peaks.

The series emphasizes the personal growth of Aoi as she overcomes her fears and builds confidence through climbing. Hinata serves as a catalyst for this development, providing unwavering support and enthusiasm. Along the way, they are joined by other characters, such as Kokona, a younger girl with a cheerful demeanor who becomes their climbing companion, and Kaede, a more experienced climber who offers guidance and mentorship. The dynamics between the characters highlight themes of friendship, perseverance, and the joy of achieving personal goals.

Each episode typically focuses on a specific climbing adventure, blending lighthearted moments with the challenges of the climb. The series incorporates educational elements about hiking and mountaineering, such as proper gear usage, trail etiquette, and safety precautions, making it both entertaining and informative. The narrative structure is episodic, with a gradual progression in the difficulty of the climbs and the deepening of the characters' relationships. The tone remains uplifting and motivational, celebrating the beauty of nature and the rewards of stepping out of one's comfort zone.