Devil x Chicken: Bravely Soul - The Fiancée From the Demon Realm

Alessa Quafurust Sytholy, one of the seven candidates for the next emperor of the Demon Realm, has a weakness. That she was timid and lacked courage. And when she was caught in a pinch, she was saved by a boy who was just a bit brave, Yuuki Hitomi. Falling in love with him because of that, Alessa tried out various erotic succubus techniques to make him into her consort, but she was foiled his childhood friend Shiraishi Sara, and the sadistic loli witch Sofia who was trying to assassinate her… Nonetheless, with the outbreak of a certain incident, the two of them becomes one! Source: LINE