The Arcen Ciel Tower (Arcenシエル・タワー?) is a tower located in the Asagao Ward of Hisakata, the primary location of the Guardian Angels Of The Sky series. The tower is located in the Shingetsu Ward in Hisakata and works as the home of several families living in Hisakata, like Aoba Sapphie and Minotori Ema's families.