"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.[3] It reached number 8 on Oricon and number 10 on Japan Hot 100. The single mark as her first double A-side 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.[1][2] The song itself was released together with the song "Ryūsei" on June 13, 2018 as her fourteenth single on three edition; Regular edition, Limited edition and Limited anime edition.[3] The single reached number 8 on Oricon, and 10 on Japan Hot 100.[4][5] The song was featured in her fourth album "Fragment".[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