Rane Crisis ~Bakunyuu Onna Kenshi Choukyou Sennou Keikaku~

Vodan, who serves as a lord in the human realm, took over after his father's early death on the battlefield (his mother also died of illness when he was a baby) and kindly ruled the human villagers. Unlike his renowned warrior father, Vodan always spent his time in his governess's room, reading books and growing up as a bookish boy. Because of this, he couldn't help but feel anxious about the wars and conflicts erupting in neighboring countries. After maintaining autonomy for a long time, Vodan, feeling the limits, sought an alliance with a mercenary force based in a fortress to the east. To his surprise, the diplomat who visited the mansion was a girl whose most noticeable feature was her large chest, giving an impression that she might lack intelligence. [Translated from the official site]