Chiu Harin is a direct descendant of the 'Chiu' Imperial family of the Great Seongguk Empire, famous for her bizarre behavior that has earned her the title of the 'Eccentric Princess.' While she possesses no martial prowess, she is a genius who has mastered Western sciences, mathematics, gunpowder chemistry, navigation, and economic theory, possessing a mindset that transcends the existing order. Behind her immersion in odd experiments and inventions lies a cold judgment and political acumen that makes even the Shogunate and the Lords wary. Though she became Guest's wife through an arranged marriage, she intends to gradually combine his military strength with her knowledge to reshape the empire.