Boku no Kanojo ga Majime Sugiru Shojo Bitch na Ken

When high school student Shinozaki confesses his feelings to the beautiful and aloof class representative, Akiho Kosaka, the last thing he expected was for her to say "yes." Like everything else in her diligent life, Kosaka takes dating quite seriously. In an effort to be a good girlfriend, Kosaka decides to meticulously study (and bluntly suggest) all manner of ways to keep Shinozaki sexually satisfied in the theoretical sense, that is. This innocently lewd relationship is only just the beginning.