"Yakusoku" (約束, Promise) is a song by Japanese pop singer Eir Aoi.

It was released on her official YouTube on February 8, 2018 as her comeback song from her hiatus,[1][2] before received a physical release together with the song "Ryūsei" on June 13, 2018 as her fourteenth single.

On 8 February 2018, it was announced that she would resume her activities after her hiatus with the release of the music video "Yakusoku" (約束, Promise) on YouTube.

[6] The music video for "Yakusoku" was directed by Yūsuke Tanaka.

[7] The video features a lyrics of the song with some footage of Eir Aoi with using blue jacket taking a photo session in the mountain, with some scene featuring a forest and also a mountain