One of the newest characters of the Touhou series, introduced in the official comic 東方茨歌仙 (Touhou Ibarakasen) ~ Wild and Horned Hermit, serialized in Chara☆Mel Febri. An enigmatic "pilgrim" with her right arm wrapped in ribbons whose search for the "Kappa Arm" led her into the Hakurei Shrine.
Due to the shackle on her left arm, her suspicious hair buns, and her title implying that Kasen has horns, there is rampant speculation among fans that she is an oni.