She is the (formerly) deceased sister of Ryoubi and Ryouna. During the Estival Versus, she was revived by Syuri and her company during the special Kagura Festival.
When Ryoubi and Ryouna were younger, Ryoki would take care of them like any parent would. This is all that she would do, until she was enrolled into Gessen Girls' Academy. Afterwards, was sent on a mission to take on yoma, but died during that mission. It was later revealed that a yoma killed her, but until Rin had given her two younger sisters that information, they believed it was Miyabi, who had killed everyone in a rampage, using the Forbidden Ninja Art: Blood Riot. However, the only one killed by Blood Riot was the yoma, everyone else died before the activation of the forbidden technique. In addition to her shotgun shield, she also uses her coffin as a weapon.
Since she hasn't been completely brought back to life per se, she still has a halo hovering over her head. She also derives much pleasure from hearing Buddhist sutras being told.
