Sotōmaru Yohakaze

"I won't be gone for long, Hisui-chan. Don't miss me too much~"

- Sotōmaru before leaving on his "10,000 Year Expedition"

Sotōmaru Yohakaze (余波風 俎豆丸 Yohakaze Sotōmaru) is a who is also the fiancé of Hisui Kawahiru. Over 500 years ago he was sent on an expedition, as Lieutenant of an unnamed division, called the "10,000 Year Expedition" to investigate a specific series of unusual events occurring in the. Though he is believed to be deceased, and thus replaced, some have claims of seeing his silhouette or actual being before dissipating. Hisui states he is alive, but simply fighting an extraordinarily difficult battle, that she is sure he will come out safe and sound from.