Kokou no Sub wa Koi wo Shiranai

Alfonso is a Sub who boasts the school's top grades and abilities, however, powers of a Dom are ineffective to him. That is, until he meets Asuka, a new student and a Dom. Asuka challenges Alfonso to a duel with the condition that if he wins, Alfonso will become his partner. Alfonso accepts with the intention of beating the cocky junior, but his body suddenly reacts to Asuka's unexpected words!

(Source: Libre, translated)