Cross-Dressing Villainess Cecilia Sylvie, Vol. 7 (manga) — Hiroro Akizakura

Double the trouble is not always twice as nice—Cecilia's finding that out firsthand while attempting to conquer the Eins and Zwei routes simultaneously! She’s trying all the classics, like helping them when they’re getting bullied or making their favorite foods...but nothing’s working! However, failure is not an option! It’s woo them or death! And so, Cecilia buckles down to try, try again until she finally wins over their hearts...!