Ken'ichi Kuraue, father of Hinata Kuraue, is an experienced mountain climber. He guided Aoi Yukimura and Hinata on a childhood ascent of Mount Tanigawa. This climb became a formative memory for both girls, forging their early connection to mountaineering. Under his mentorship, they witnessed a sunrise from the summit—a pivotal moment that later reignites their shared passion for climbing. His role as a catalyst for their outdoor pursuits anchors the series' narrative foundation, centering on overcoming challenges through mountaineering.