Hiro is a mute guard-in-training who has never found it easy to connect with people. Most of the town has settled on calling him things like creep, weirdo, and kid rather than learning his name. The one exception is Saki — his closest friend since childhood and everything he is not: outgoing, curious, always looking past whatever she is not supposed to see. When Saki decides she wants to explore the world that is officially off-limits to both of them, she wants Hiro with her.