"Tabun" (たぶん, "Probably") is a song recorded by Japanese duo Yoasobi from their debut EP, The Book (2021). It was released on July 20, 2020, as a digital single, through Sony Music Entertainment Japan. The song was based on the Yoasobi Contest Vol. 1-winning novel of the same name written by Shinano. A middle tempo song, it depicts a couple breaking up in the morning. The song also accompanied the movie of the same name, Tabun, based on the same novel. The English version of the song, titled "Haven't" was included on the duo's first English-language EP E-Side, released on November 12, 2021.