Sakuya

Sakuya (, Blooming) is a spirit sword, which chose Yuki Nonaka as its wielder.

Description
Sakuya is a spirit sword, which shares the same name as the Shinto Goddess, Konohanasakuya-hime from Shintoism, as such, it gained a great deal of spiritual power over time due to their belief. The spirit sword chose Yuki due to her unwavering faith and compassion toward Rei Serizawa even after the incident from five years ago. Due to their connection to Mount Fuji, the further the sword is from the mountain, the lower the strength of Sakuya will be, as such throughout the series, Sakuya hasn't displayed much of its original strength.

Inside the Underground, Yuki was unable to display much of its power, but after an Daemon in the Underground had opened a small portal leading into the Human World letting her use its power.

In Volume 10, during her and Mio's battle against Seiryuu and Qióngqí, Sakuya started to turn from silver, pink, and crimson displaying its full power, causing all the sakura trees around her to bloom, then displayed immense power that outmatched the Azure Dragon Doll and Qióngqí, one of the Four Perils.

Trivia

 * Sakuya has both Metal and Wood Elements.
 * Sakuya choosing Yuki could be due to Konohanasakuya-hime's love toward her husband, Ninigi-no-Mikoto.