Five-seveN is the vice-captain of Team FN, which is specially responsible for investigating extraordinary or unexplained events. She first appears in night battle of Chapter 6. She is very optimistic and popular among G&K members, but she is also ambitious and vicious, which shows when communicating with AR FALFAL , who is the captain of Team FN, by stating she will replace FAL as captain someday. Though she always says that she can't get along with FAL, she is also one of very few G&K members that truly understands FAL's thoughts and actions, she is both the best friend and rival of FAL at the same time. When FAL is in trouble on the battlefield, Five-seveN will always have her back.