Read manga: A Story About A Hero Exterminating A Dragon-Class Beautiful Girl Demon Queen, Who Has Very Low Self-Esteem, With Love!

manga
Summary:

Iver is a dragon maou who stopped trying after historical heroes defeated her every time she resurrected. But the present day hero, Mirio, who found the holy sword by pure chance falls in love with her. And thus forms the couple of the maou with no self-esteem and the dopey hero. This is a story of how they come to know each other, fight, and find happiness.