Tama is nine-years-old, the youngest of the Yagami sisters, and is in third grade. In contrast of Tsurugi, despite Tama's young age, she has the appearance of an adult woman. However, she has the innocent personality of a girl her age or even younger.
Her name is based on Yasakani no Magatama. Tama was created by Tsurugi to be the next vessel of Amaterasu's power after Sasami.