"Haruka" (Japanese: ハルカ) is a song by Japanese duo Yoasobi from their debut EP, The Book (2021). It was released as a single on December 18, 2020, through Sony Music Entertainment Japan. The song was based on short story, Tsuki Ōji (lit. "Moon Prince"), written by screenwriter Osamu Suzuki. The music video premiered alongside the single release.[1] The English version of the song was included on the duo's second English-language EP E-Side 2, released on November 18, 2022.[2]
"Haruka" was described as a song about encounter and farewell, drawn from the perspective of "something" that has watched over the growth of a girl more than anyone else.[3] It is composed in the key of C♯ major at 100 beats per minute with a running time of 4 minutes and 4 seconds.[4]