Setsuna is the former goddess of the Spirit World (Maid's World). In the past, she was rescued as a "tsuru" ("crane") by Takuro Mutsumi (Goro's father), who became her "Master." Her wing injury was treated by Takuro and when she was finally healed, Goro's father let her go. Setsuna later died and was sent to the Maid's World. There she became a guardian angel and then goddess.

As a goddess, Setsuna reunited animals who were separated from their owners as guardian angels. She was the one who was responsible to the reunion of Goro Mutsumi and his twelve pets. Disguised as a fortune-teller, Setsuna told the then very unlucky Goro that luck will come to him. She even added a spell to Goro's cellphone that allowed the twelve guardian angels to be reunited with their beloved "Master." Setsuna was also the one who revealed that Goro is the reincarnation of Seijya, the sage who stole the divine powers of the Four Saint Beasts and sealed the Beasts away for centuries in order to prevent the impending destruction of the humans and, in next life, to create a new world where humans and animals can live as equals with the Saint Beasts' help.

In the anime "Tenshi no Shippo Chu!," Setsuna gave up her throne. Thirty years after her rescue as a crane, she was reunited with her master, Takuro. During the reunion, Setsuna confessed her feelings of love towards Goro's father. Because of this, Setsuna violated "The Maid World's Commandments" which prohibit confession of romantic feelings towards the master and saying of forbidden word, "love" (NOTE: The Four Saint Beasts punish the violators of the commandments by reversing them in their original animal forms. In addition to this, the violators' memories of their masters are also completely erased.). Setsuna returned to her original crane form in the presence of Takuro, Yuki, Mika, Ayumi and Ran. Her memories of Takuro Mutsumi were completely erased. Setsuna was succeeded by Yuki as goddess of the Spirit World.