Sputnik Sweetheart (スプートニクの恋人, Supūtoniku no koibito) is a novel by Haruki Murakami, published in Japan, by Kodansha, in 1999. An English translation by Philip Gabriel was published in 2001.
The plot features three main characters: Sumire, Miu, and 'K'.
The novel's protagonist, Sumire, is an aspiring writer who survives on a family stipend and the creative input of her only friend, the novel's male narrator, 'K'. 'K' is an elementary school teacher, 25 years old, and in love with Sumire, though she does not quite share his feelings. At a wedding, Sumire meets an Ethnic Korean woman, Miu. The two strike up a conversation and Sumire starts to work for the older, married woman. Over time, she realises that she is attracted to her, and thus, that she might be a homosexual.