Masashi Hamauzu
Following the digital success of her debut song, Sugawara released her debut single, "Ano Hi no Yakusoku" on September 30, 2009. On September 3, 2009, at the "Final Fantasy XIII" premiere, it was announced that she would perform its theme song, "Kimi ga Iru Kara". Composed by Masashi Hamauzu, Sugawara performed the song with a live orchestral accompaniment at the premiere. A single for "Kimi ga Iru Kara" was released on December 2, two weeks before the release date of "Final Fantasy XIII".