Futago no Ouji ni Futago de Kekkon Shita kedo "Ja nai Hou" dakara Yami Mahou wo KiwameruFutago no Ouji ni Futago de Konyaku Shita kedo "Ja nai Hou" dakara Yami Mahou wo Kiwameru; 双子の王子に双子で婚約したけど「じゃない方」だから闇魔法を極める; The Twin Princes got Engaged to Twins, but Because I'm "The Other One" I Decided to Master Dark Magic