Princess Septième Rodelia, who appears in Chapter 15 "The Unforgettable Princess" and Episode 13, "Crude, but Elegant", is from the neighboring kingdom of Rodelia. She is the seventh in line to Rodelia's Imperial Throne. She happens to be acquainted with Alice.
One of seven children, Princess Septième lives by herself in a section of the family castle, Chateau de Lezan Dou Crepuscule, only meeting with her six siblings for dinner. Then again, even dinner can be a dangerous time for her - as well as the others for they may resort to assassinate each other for the throne.
Princess Septième is distantly related to Alice's grandfather, and thus came to know Alice.
The Rodelia children try to outwit and dominate each other - which includes assassinations. Earlier in her life, Septième was haunted at the sight of her food taster - who was also a good friend - dying from poisoning as a result of tasting a birthday cake Septième's siblings made for her. Since then, she hardly trusts anyone, always looking at others with suspicion.
However, upon her latest visit in the Imperial country, she has a good time with Martis and concludes she can trust him. She even leaves him a departing kiss - much to the shock of everyone.
As one of the Rodelian royal children, Septième is trained since birth to look for weaknesses in others and to take advantage of those weaknesses for personal gain. She has a photographic memory, having the ability to remember anything she's heard or seen. It is for this reason that she often interacts with people she hasn't seen in years as if she just met them yesterday. According to Alice, Septième is a strange girl who could speak four different languages by the age of three.
Princess Septième was on her way to the Royal Empire to try to free a citizen of the Rodelia Kingdom who had been arrested for smuggling. However, seeing an opportunity to get away from her aide, she ditched the train and tried to hide in a restroom - where Martis was using at the time. Taking advantage of the situation, Septième dragged Martis around town as her guide. But was lucky Martis was around when she found herself in a dangerous situation, for which the young soldier was able to save her.
On an earlier visit years before, Septième remembered a particular hot dog stand with a black and white checkered awning in the capitol, and wanted to try the wares it served. However, when she returned she found it gone. Later, with Martis' help, she found the owner had owed heavy taxes (Martis had been looking for that same hot dog stand when he was abandoned by Oreldo). As a result, his vending license was suspended, so was forced to close. But she then found that the stand had re-opened near the slums and tracked it down with Martis. She then tried to force the owner to give their meal for free - in exchange for not reporting him for running an unlicensed stand and his failure to pay his taxes. But when Martis paid the man anyway, Septième ran distraught into District Zero - a particularly nasty section of the slums, one even the police didn't patrol. She was confronted by thugs who wanted to kidnap her, but Martis followed in and thrashed the hoods, ending up slightly injured in the process.
Once the two returned to Army Intelligence, Septième allowed the Empire to keep the man that was confined, in exchange for Martis to once again be her escort if she returns. She then did something shocking afterwards - she kissed Martis, then departed. This was very embarrassing for Martis - especially when Webner found out, for which she gently teased the poor guy about it!