A style of women's shoes characterized by a single strap across the top of the foot in place of laces or a zipper. Usually black, short-heeled or flat, and very smooth-featured, with a simple buckle to hold the strap tight. Commonly seen on school uniforms, lolita fashion, and fetish porn stars.
Not to be confused with loafers which can also have a strap but running over a leather top. Example post #1132658: Kousaka Kirino (left) is wearing loafers while Gokou Ruri (right) is wearing mary janes.