In 2060 Seoul, obsolete helperbots live quietly in aging apartment buildings. Oliver, a Helperbot-5, follows the same routine each day while waiting for his former owner James, who promised to return. Although James now lives on Jeju Island, a monthly jazz magazine sent in his name gives Oliver reason to keep waiting.

One night, Claire, a Helperbot-6 from the neighboring apartment, knocks because her charger has failed. Oliver allows her to recharge in his room and begins lending her his portable charger. Their repeated encounters gradually become companionship.

Claire learns that Oliver has been collecting coins for a journey to Jeju to find James. Because public transportation is dangerous for helperbots, she borrows a car and offers to travel with him. Pretending to be a human couple, they begin a road trip across Korea.

On Jeju Island, Oliver discovers that James died a year earlier and that his family now uses a newer helperbot. James left Oliver a vinyl record as a final gift. Claire comforts him, and together they visit a forest filled with fireflies.

After returning to Seoul, Oliver and Claire recognize that they miss each other and conclude that what they feel may be love. Their happiness is shadowed by the difference in their remaining lifespans: Claire’s failing battery may last only another year, while Oliver is expected to function much longer.

Unable to face the separation ahead, they agree to erase their shared memories. Oliver returns to his former routine, apparently unaware of their relationship. When Claire once again knocks with a broken charger, however, he instinctively moves his plant aside, opens the door for her, and watches while she recharges. Asked whether everything will be all right, Oliver answers, “Maybe.” (Korean Original Version)