Kaguya Otsutsuki was a member of the Ōtsutsuki clan and the matriarch of a branch family, including her children Hagoromo and Hamura. Long before the founding of the hidden villages, during an era of endless war, Kaguya consumed the fruit of the God Tree and became the first wielder of chakra on Earth, before later merging with the tree to become the Ten-Tails.

A millennium ago, Kaguya and Isshiki were both sent to cultivate a God Tree on the planet Earth and harvest its Chakra Fruit, with which she was to provide for the main family of her clan from another world. According to Amado, Kaguya was a low-ranking member of the clan chosen as a sacrifice to the Ten-Tails, which would nurture the development of the God Tree.Instead, Kaguya desired the chakra fruit herself; betraying Isshiki in the process and leaving him for dead.