okobo
Japanese platform sandals that were traditionally worn by geisha during their apprenticeship. The most notable type in fanart are the black-lacquered kind with red straps.
Technically, the black-lacquered finish is only worn mainly during summer, and the color of the straps used changes depending upon how far along the apprentice geisha is in her training.
Not to be confused with geta, which have two square "teeth" on the sole instead of being made as a solid block, or zouri, which are flat like flip flops.