Asahina Yuki, a high school girl who feels stifled by the cold efficiency of modern life, makes the decisive choice to leave Tokyo and move to her aunt's house in the port city of Onomichi, Hiroshima. This world is one where automata, highly advanced mechanical dolls, have become an integrated part of daily society. Upon arriving at her aunt's home, Yuki is surprised to discover that the household already includes one of these automata. Unlike the impersonal machines she expected, this automaton possesses a remarkably natural capacity for interaction, blurring the line between tool and living being. The story centers on the emotional and personal journey that unfolds from this unexpected encounter, exploring the quiet connection that develops between a girl seeking genuine human warmth and an automaton whose inner world remains a gentle mystery against the atmospheric backdrop of Onomichi.