Shin Roselia Oukoku Monogatari

A 17-year-old girl named Roselia has recently become queen of the small frontier kingdom known as the Land of Roses. During her coronation, attended by many foreign dignitaries, she is portrayed as both a gifted and beautiful young woman to mask the kingdom's vulnerabilities. However, larger nations view this young monarchy as a target and send assassins to eliminate her. Meanwhile, a man named Hernan has gained the queen's trust, though his true background remains unknown.