Manga Like Wo Xi Huan Ni De Xin Xi Su

As a good-looking Beta boy from a good family, Duan Jiayan's life has been smooth sailing for many years, until he runs into Lu Xingci in high school. Lu Xingci's family is richer, he's taller, he's a better basketball player, and their grades aren't even close. Even his own friends can't help but praise Lu Xingci sometimes. What's worse, that girl Duan Jiayan had set his sights on admitted that she has had a crush on Lu Xingci for years. Ever since then, Duan Jiayan has disliked Lu Xingci. But during a medical exam, he was told that he is a late-blooming Omega, and because he became an Omega so late, it came with serious side-effects. Any Alpha who comes near him will feel a painful sensation and become violent. And Duan Jiayan is allergic to the pheromones of all Alphas, all except for Lu Xingci. (Source: Bilibili, translated)