Jiu is a very kind and social girl who is related directly to Japanese royalty. She disregards her responsibilities due to the fact that the Japanese royal family has no direct power over Japan. Due to her family relations, she goes to the school and is apart of the Karate Club and is the strongest female there. She does well in her studies, averaging in the B's range. However, she chats with people with a built in suspicion, and she seems to know something about you. A rumor is circulating currently that she has a crush on Taro, though she hotly denies it. It's probably best to get rid of her, seeming that she may know about you or Senpai.
OVERVIEW OF JIU:
Jiu has a kind and well-mannered personality. Her parents home-schooled her in elementary and middle in order to teach her the ways of the land for how to act as a royal. They have high expectations of her, and expect her to marry a suitable man to carry on the linage of the Emperor. However, she refrains from telling anyone this even though it isn't a secret.
She does know Ayano, but keeps a respectful distance, as with everyone. However she is very paranoid near certain people and sometimes had a quirky attitude that is the reason for her low popularity. She does have some friends but not all of them are exactly true friends. Despite her club affiliation, she does not fight outside the club because she is aware of her surroundings and can stop an attack before one even launches it. However, if she was caught off guard by an attack that was not psychical, she could possibly be harmed (such as poison).
A rumor around the school is that Taro Yamada is the assigned suitor her parents have chosen, however it is not true. Some people go too far with pranks relating to the two, which causes Ayano to believe the rumors and act upon them just in case. Actually, the assigned suitor is Jiu's unknown crush, who her parents chose for her after observing who she liked at school.
Jiu tends to be a bit of a nervous wreck towards certain people, including her crush. She is usually most vulnerable at this point. However, she is the most confident during her club meetings and when doing her hobby, which is photography. Despite this fact, she does not join the photography club because she finds some of the members obnoxious and prefers to practice her hobby alone, without a big audience.
She tends to hang out with many friend groups at certain times, as well with individuals. She likes everyone the same, but keeps a special opinion about several people, including Ayano. She prefers to stay away from Ayano, as she has a certain nervousness about her. This is not readily apparent and to others, it seems like she likes Ayano just fine, even referring to her as Yan-Chan. But Jiu knows something about her, claiming she gets a strange vibe, but is regarded as paranoid by others.
(For more about the crush, see Luna's comment below.)