The wealthy blonde daughter of the school's headteacher, Sena shows a dislike of all things "ordinary." She is both attractive and academically successful, but her resulting arrogance leads her to be disliked by her female peers. Their admiration eludes her, much as she desires it; she treats her male classmates only as servants to be used, although many of them would like to be her boyfriend. Nonetheless, she holds Kodaka to a higher standard. Kodaka concludes that she is the weirdest member of the club, as she is able to warrant weird and disgusted looks not only from Yozora and Kobato but also from Yukimura and Rika. She enjoys playing video games—including dating sims and eroge—partially because they allow her to make female (if virtual) friends. Yozora calls her "Meat" (Niku) an insulting nickname which she secretly likes because it is the first she has ever received. Her father is a friend of Kodaka's father, and pulled strings so that Kodaka could attend St. Chronica's. She really likes Kobato, since she always gets really excited when she sees her. Usually, when Sena and Yozora fight, Sena usually runs from the room crying and shouting "Stupid Yozora! Go die!." It is hinted that she has feelings for Kodaka.

Xin is one of Kingdom's main characters. He grew up like a slave together with his best friend and fellow orphan, Hyō, in a small village, but the two always dreamed of leaving their social class by becoming the world's greatest generals. Not much is known of Xin's family or past. Xin has a temper, but he also has a good heart. He is clearly loyal to his friends since he vows to not stop until Hyou's is fully avenged-even at the risk of his own death. His hot temper also makes him clash with Ten and they tend to bicker like siblings constantly! Xin's swordsmanship skills are very good due to his constant training over 1000 times with Hyō, but he also has monstrous strength and is very agile. In the fight with Jo Kan, it seems that Shin also has the ability to adapt very quickly in order to get the upper hand in battles. Xin dream is to become the world's greatest general, so that his name will be known even in the heavens. He shared this dream with Piao and now sets out to fulfill it for both of them.