Chu Yi Ping is a reclusive man who, after injuring his hand, receives—with his uncle’s help—an experimental humanoid robot equipped with artificial intelligence to care for him. Yi Ping is reluctant at first, but then discovers a friend in Heng 9—so much so that he asks him to make a bucket list for them to complete together. Before the list is finished, Heng 9 malfunctions. After Heng 9 is reset, Yi Ping can no longer relate to him the way he did before. How will he now cope with the suffering he feels?