"Gake no Ue no Ponyo" (崖の上のポニョ, Ponyo on the Cliff) is the eponymous theme song to the Studio Ghibli film Ponyo, released on December 5, 2007 (though gaining popularity with the release of the film in August 2008). It was performed by folk group Fujioka Fujimaki and then eight-year-old Nozomi Ōhashi.

The song was written in collaboration between veteran Ghibli composer Joe Hisaishi, with lyrics by the film's supervisor Katsuya Kondō and director Hayao Miyazaki. When Hisaishi originally saw the storyboards for the film, he immediately thought up the melody for the song. However, as he believed it was too simple a melody, he did not mention it for two to three months. He eventually showed the song to Miyazaki and producer Toshio Suzuki as he could not get it out of his head. They both believed such a simple song was fitting for the film.

Other than being promoted in commercials and in the film Ponyo, the song was used in commercials for Mitsuya Cider. Fujioka Fujimaki and Nozomi Ōhashi performed the song on the new year's song contest Kōhaku Uta Gassen, making Ōhashi the youngest participant after 59 years of airing.

The song was an extremely successful long-seller on Oricon's physical single charts. The song initially only charted for one week at #115 after its initial release in December 2007. It began charting again lowly in below the 100 mark at the beginning of July, and broke into the top ten at #6 by the end of July. The song then spent 11 weeks in the top 10, peaking at #3 for four weeks. The song charted in the top 50 for 15 further weeks (breaking into the top 20 around new years, due to Kōhaku Uta Gassen), and finally stopped charting in the top 200 August 2009, spending more than an entire year on the charts.

On the Billboard Japan Hot 100 (combined physical sales and airplay), the song peaked at #4, and was the 17th most successful song in 2008. Digitally, the song peaked at #1 on RIAJ's monthly ringtone chart, and has been certified platinum for full-length cellphone downloads and double-platinum for ringtone downloads.

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