Singer Aoi Eir will release her 14th single "Ryusei / Yakusoku" on June 13. This will be her first single release since resuming her activities. 

As expected, her new song has received an anime tie-up. "Ryusei" will be used as the opening theme for anime 'Sword Art Online Alternative Gun Gale Online.' 

The single's Limited Edition will come with a DVD containing the PVs for the title tracks as well as a photo book. Meanwhile, the Anime Edition DVD will include a non-credit opening movie for 'Sword Art.'

Source: Oricon