Jouzu ni Dekita ne, Watase-san

A second sex, Dom/Sub, emerged in the evolution of mankind. Doms dominate Subs and Subs are subordinate to Doms. Watase, who is a "sub but top," distanced himself from sex play due to the trauma of being almost forcibly dominated by his Dom lover in the past. One day, he went to a shop that specialized brothel in order to satisfy his lust. When he confesses to Touma that he is a submissive top... he gets an unexpected reply, "I'm a dominant bottom!"

(Source: Takeshobo, translated)