Jeanne Euphoria

Jeanne is the crown princess and commander of the military of the Gran Chaos Empire as well the younger sister of the current Empress Maria Euphoria.

Jeanne is described as the opposite to her idealistic sister and shares many of the realistic viewpoints of Kazuya Souma. She also possesses a keen mind and is able to negotiate with Friedonia's Prime Minister Hakuya Kwonmin.

She also enjoys complaining about Maria and spends time with Hakuya complaining about their respective masters using the Jewel Voice Broadcast. According to Maria she has become more lively since she began her complaining sessions.

(Source: How a Realist Hero Rebuilt the Kingdom Wiki)