"Ignite" is a song by Japanese singer Eir Aoi. It was released as a single on August 20, 2014. The song was used as the opening theme for the anime series "Sword Art Online II". Known for its upbeat tempo, energetic melody, and powerful vocals, "Ignite" became widely popular among fans of both Eir Aoi and the anime series. The song's lyrics reflect themes of determination and perseverance, fitting well with the action-packed nature of the series it was featured in.