Shampoo sees a red string.
The salesman said that if the red string is tied on the little finger of someone and yourself for five hours, that person will love you forever. So Shampoo buys it. Shampoo goes over to the Tendo home to try to put the string on Ranma's little finger. Ranma was sleeping. But Akane comes into the room to return a book, so Shampoo runs away before she can tie the string.