If you're looking for manga similar to Romance wa Tsurugi no Kagayaki II Plus, you might like these titles.
Synn is a hard-luck high school student. One day, he becomes student council president. But his job as president includes getting rid of mazoku (denizens of hell) that appear in his town as well. Also, he is informed that his father is the Maou (king of demons) and he is supposed to succeed to his position in the future. He has to fight against mazoku as the president, but his father is the leader of those mazoku. Well, will he be able to keep it a secret and enjoy his school life?
One day, Rena found a magic mirror that can grant any wish. To choose who will get that mirror, the club members begin the club activities, it's the battle in pairs. Mion teams with Keiichi. While they are in preparation, Satoshi returns. Shion and Satoko team is very glad, but Mion and Rika have an uncomfortable feeling about that...