Yume no Kochō

is a mystical entity with unique powers.

History
Sometime in her past, Setsuna was cursed by the Dream Butterfly to be unable to sleep or dream and had her memories of her past erased, including her own twin-sister Towa. Now, Towa, Setsuna and Moroha go on a quest to capture the Dream Butterfly and undo Setsuna's curse. It was later seen circling a comatose Rin in the Goshinboku as the Spirit of the Goshinboku observes her with Sesshōmaru.