Uwakisareta Jimi Reijou ga Oukyuutsuki Biyou Advisor to Himitsu no Lesson! Uwaki Otoko wa Sutete Koori no Koushaku Reisoku-sama wo Toriko ni Shite Misemasu浮気された地味令嬢が王宮付き美容アドバイザーと秘密のレッスン！～浮気男は捨てて氷の公爵令息様を虜にしてみせます～

Janet is constantly being cheated on by her fiancé, She lacks self-confidence and cries all the time, unable to say anything. She can't muster up the courage to say goodbye to him, her beloved first love. One day, Janet is approached by a royal beauty advisor, Amandine. Accepting training from a woman so beautiful that it's hard to believe he's a crossdresser, Janet's new life begins! (Source: Comic PASH!, translated)