Dear Antique,

In a world where humans and androids are connected in a master-servant relationship, Marius, an android mechanic, meets Misha, an antique android who has lost his memory. Misha seeks a new master, sings songs, and sometimes refuses orders. Marius is interested in Misha, who deviates from the norm for androids, but is it because of his nature as mechanic, or...? (Source: Shueisha, translated)