As a child, Aoi Yukimura adored mountains and was passionate about climbing. However, a playground accident has since left her afraid of heights, turning her toward indoor hobbies. Unfortunately, now a shy and timid first-year high school student, Aoi has become so absorbed in these pastimes that she can barely socialize with others, leaving her practically friendless. It is only when she runs into the lively Hinata Kuraue, an old friend from her climbing days, that things start to change. Impulsive and high-spirited, Hinata insists on having Aoi join her in all sorts of climbing activities. Though reluctant at first, Aoi quickly finds that her time with Hinata brings back fond memories of their childhood and soon decides to start climbing again. As the return to her past hobby starts to bring her out of her shell, Aoi finds herself gaining close friends, taking on new challenges, and continuing to find her own encouragement to climb.

Surrounded by a forest and a gated entrance, the Grace Field House is inhabited by orphans happily living together as one big family, looked after by their Mama, Isabella. Although they are required to take tests daily, the children are free to spend their time as they see fit, usually playing outside, as long as they do not venture too far from the orphanage—a rule they are expected to follow no matter what. However, all good times must come to an end, as every few months, a child is adopted and sent to live with their new family, never to be heard from again. However, the three oldest siblings have their suspicions about what is actually happening at the orphanage, and they are about to discover the cruel fate that awaits the children living at Grace Field, including the twisted nature of their beloved Mama.

Continuing their treks through the high peaks of Japan, the mountaineering girls are back for more! First-year high school student Aoi Yukimura, a shy girl with a fear of heights, and her wildly energetic friend Hinata Kuraue set out once again to conquer the perils of backyard camping trips, summer homework, and even a climb on the mountain of their dreams. Joined by middle school student Kokona Aoba and their knowledgeable upperclassman Kaede Saitou, the squad members are ready to take on whatever slopes and challenges they might face, no matter how steep. Through their shared hobby of mountain climbing, they bond closer than ever and even make new friends on trails all over the country. Whether it is just a local hill or the tallest mountain around, nothing is too much for Aoi and the crew to handle. They will climb, stumble, and rise to even greater heights together!

Various stories about a group of animals that live together in a forest. The stories are adaptations from the many children's books written by Thornton W. Burgess.