Ookami Shoujo to Kuro Ouji, Masamune-kun no Revenge Recommendations
They are both comedy, romance and school animes.
Both male MC-s are not in love with heroine at first.
Adagaki from Masamune is not interested in boys, because she thinks boys will just use her. And Sata from Ookami is not interested in girls, because he thinks girls are not taking relationship seriously.
Also in both animes new love rival appears.