Going to make this short
Ranma and Shampoo don’t match or compliment in personalities but would fight good together.
Shampoo wants to marry Ranma because so lost a match to him do to Amazon law.
Ranma isn’t interested in her, just keeps running away.
He is afraid of cat form Shampoo, what a loser.
Than manga has concluded with Shampoos apparent lost but the marriage is canceled because Ranma has too many suitors.