Katatagae or Katachigae is one of the customs based on Onmyodo (way of Yin and Yang; occult divination system based on the Taoist theory of the five elements) performed from the Heian period (794-1185).
方違え（かたたがえ、かたちがえ）とは、陰陽道に基づいて平安時代以降に行われていた風習のひとつ。