The Sohma Curse

Having stumbled onto the Sohma secret, Tohru may lose her place in the household before she ever settles in, and there is a graver threat looming: the family's leader could choose to strip the memory from her mind.

The episode opens with Tohru rushing to a passing postman, clutching the animal forms of Shigure, Yuki, and Kyo after a falling wooden plank knocked her into them. She begs the man to help, but he brushes her off as unhinged and simply hands over the mail, while the clever dog that is Shigure assists his "owner" in collecting it. Once the postman goes, Shigure lays out the curse: for generations the Sohmas have changed into zodiac animals whenever they are embraced by someone of the opposite sex. He names Yuki the rat, himself the dog, and Kyo the cat, then adds that they return to human form without any clothing, a detail that sends a stunned Tohru straight into a wall. The following morning she washes her uniform after a rough night.

This is the 2001 telling of a story the 2019 series adapted as "They're All Animals!" The script draws on Chapters 2 and 3 of the manga.