Kuro Koushaku to no Himeyaka na Keiyaku

Princess Arca is betrayed by the one person she thought she could trust, resulting in the murder of her entire family and a tragic end to her first life. Given a second chance, Arca does whatever she can to not let the past repeat itself, including entering a contract with the demon duke Mayhem. Mayhem is willing to help Arca obtain a happy ending for her family. However, it will come at the price of Arca giving up her own happiest memories... (Source: Tappytoon)