A teenager named Haruka is left traumatized and haunted by silence after her best friend dies on a hike where there was no cell phone service to call for help. To overcome her feeling of helplessness, she discovers the world of amateur "ham" radio. Guided by a group of new friends and mentors, she earns her license and learns various skills, from making worldwide contacts to providing emergency communications.

Her journey comes full circle when she uses her radio skills to save an injured hiker in a remote area, finally conquering the trauma that first led her to the hobby. Through ham radio, Haruka not only finds her own voice but also discovers a connection to a hidden family legacy and the power to help her community.