The Mirror Mansion is an old, isolated inn located in the wilderness. It is built in the Western style and is named for the large magic mirror located in its lobby. This mirror is possessed by a spirit which will take on the appearance of anyone who looks into it. To prevent this from happening it is normally covered by a heavy protective seal curtain with the word "Taboo" on it.
While on a training trip, Genma and Ranma Saotome got lost in the rain and stumbled onto the Mirror Mansion. They were welcomed by the innkeeper who warns them not to slip on a banana peel, fly into the forbidden curtain ahead and see the terrible secret beneath it. As he's saying this, Genma ate a banana from a bowl of fruit on a table in front of the mirror and tossed the peel onto the floor, causing Ranma to slip on it and fly into the curtain. She ripped the curtain when she grabbed onto it and fell, exposing the mirror. After Ranma gazed into the mirror, a duplicate copy of her emerged. The innkeeper then explained the mirror's history. It was made a century ago and previously owned by a young woman of the Monkey family. The woman was so beautiful and enamoured of herself that she would gaze into the mirror daily, seeing nothing but herself. After years of doing this, she fell ill and died, bitterly regretting that she had not had a boyfriend. Her spirit then came to possess the mirror, as since then it would take on the appearance of whoever looked into it and aggressively flirt with anyone of the opposite sex. As it would take a week to make a new protective curtain, the copy returned to Furinkan with Ranma and Genma and began to cause trouble.
After a week, both Ranmas and Akane Tendo returned to the Mirror Mansion to return the duplicate Ranma to the mirror. The copy gave Ranma a gift which turned out to be the magic compact that the innkeeper had earlier given to them in order to contain the copy if she became troublesome. Ranma was sucked into the compact and the copy tried to take him with her back into the mirror. Akane was able to stop it by hitting her with a bowl of fruit, but in a repetition of the events the week before that started the whole incident, Ranma slipped on a fallen banana and again flew into the new curtain, ripping it as he fell. However as this time he remained male, a male duplicate came out of the mirror vowing to hit on cute girls. When the two duplicates saw each other, they both fell in love with each other. They were taken back to Furinkan for another week while another seal curtain was made for the mirror.
- The idea of a mansion containing a mirror that creates an evil clone of the person using it due to a curse caused by a narcissistic girl appears to be a parody of the Scary Book: Reflection by famous manga author, Kazuo Umezu.