Kaguya Yamai is a Spirit, a powerful being in the 'Date A Live' series. She is one half of the Yamai Sisters, with the other being Yuzuru Yamai. Kaguya is known for her energetic and competitive personality, often engaging in playful rivalry with Yuzuru. She possesses wind-based abilities and wields a lance called El Re'em. Initially, Kaguya and Yuzuru were a single entity known as Yamai, but they split into two separate Spirits. Throughout the series, Kaguya and her sister challenge Shido Itsuka, the protagonist, who must seal their powers through forming a bond with them.