In 2008, when asked about a Monaco character, she was described as being "way more than healthy/energetic" and Hidekaz Himaruya said that "a more leisurely optimistic, but refined in some respects sort of feeling" would be good for her character. In her official profile she is described as prideful girl who gives off a stylish impression. She speaks like an older man in some respects and her great intelligence has protected her country to the present day. She's variously prone to worrying and constantly thinks about the state of the world and economic things while gazing at the sky, but when you speak to her she's surprisingly calm and sociable, though she worries about the boisterousness of other countries more than anyone else. A young honor student, she's an optimist at heart despite her stern appearance, and does ballet as a hobby. Her volume 4 profile states that she believes behaving cleverly is best and that she's against eating tuna.

Known for her beautifully structured casino which she, herself is not allowed in by law, she puts her efforts into tourism, interior designing, and cosmetics. Despite not being allowed in the casino, she's shown to be a bit of a gambler and confident in her strong skills, betting a date with Seborga on a game of poker. She also displayed confidence in their plan during Halloween to get others to join them. She also owns a Japanese-style garden which is not far from the casino.

(Source: Hetalia Wikia)