The "Closed Eyes of Love". Extra Stage boss of Touhou's Subterranean Animism, and later a playable character in Hopeless Masquerade, Urban Legend In Limbo, and Antinomy Of Common Flowers
A satori and a natural telepath, Koishi has sealed off her mind-reading ability (represented by the fact her third eye is closed) so she would not experience the fear and loathing her older sister Satori suffered. This indirectly gave her a new and even more terrifying power, the ability to read and manipulate the subconscious mind. Her own conscious mind was sealed away as well, and she no longer has a real personality or desires. Koishi now wanders Gensoukyou, going wherever her subconscious wills her.
Koishi is portrayed with either silver or green wavy hair and green eyes. She wears a yellow collared shirt with long and wide sleeves with frills and a green skirt with floral print. On her head, she wears a black hat with a yellow ribbon around it. She is easily identified by her blue third eye, an external eyeball that is wired to her clothes by veins/cords (often forming a heart of string).