|Nanami Knight Bladefield|
|Class and Year||1-F|
|Physical and Vital Statistics|
|Manga||Volume 1 Chapter 1|
Nanami Bladefield is the older half-sister of Hakua and Souta as well as the the thirteenth princess of Bladefield. Both sisters are quite formal with one another calling each other the thirteenth or the fourteenth because of how often they see each other. She, Souta and Hakua all have different mothers who are all Japanese.
When she introduces herself to Souta, she does not raise a flag like the other characters. She shows interest in Souta's ability, and serves as the "princess knight" in Souta's party.
Similar to her brother, she is rather serious and often plays the straight man to some of her friend's acts. She gets irritated very easily and when she gets embarrassed she always hits that person.
On the other side, she has a kind personality and tells Souta that he should make friends. She can be see as friendly as shown when she became close friends with those of the dorm and befriending Serika Ginyuuin.
She and Souta first met by a trafic incident where Souta saved her from a truck. Later on Souta joins her class. She was the first person who realised that there was something strange with Souta, because he always looks on people their heads before talking to that person and that at the incident she saw him do something and he tells her that he broke her flag.
Later on it's revealed that the King has died. Ellia also reveals that Nanami and Hakua are actually not the king’s children, but rather his own.
When Souta erased everyones memories about himself (episode 11), Nanami was the only who still remembered him. Nanami later on finds out that everyone forgot about Souta. During their graduation day, all Quest Dorm members were going about their separate ways. The Quest Dorm is said to be demolished soon. Nanami breaks into Souta's rom, and find the letter that Souta received, written by her handwriting, thus breaking Souta's Protect Mode. Riru, who always remembered everything, finally tells Nanami the truth; Nanami is Souta's missing sister.
Separated into two, half of Nanami is locked in the jail in Principality of Bladefield, in which she manages to escape and hides inside Ruri. Understanding everything, Nanami unites with her other self. Denying the bittersweet end of the fairy tale, Nanami alongside the Quest Dorm members aim for the happy ending, and went to the underground passage to open the gate to reach and help Souta.
During Christmas, Nanami was brought by Serika who had to spend alone time with Souta, she was selected so Souta wouldn't flirt with her. Nanami stated that she was being too harsh but Serika pointed out that she brought Nanami to defend her from Souta if he tried something with her before Nanami assured her that she was on her side.