what will happen if a guy born on July 31, 1976 and the girl born on April 7, 1976 .

You are right about the animal signs. As for the relationship, Chinese astrology shows that it may be just so so, because you have much common. Both of you are stubborn and aggressive. Once there is a conflict, it will affect your relationship. Anyway, if U you really love each other, there is amendment: 1. spare enough personal space for each other; 2. learn to compromise upon the possible argument.