|Japanese name:||喜界島 もがな|
Originally the ace of the swim team, Kikaijima serves as the treasurer of the Student Council. She is close friends with Yakushima (the swim club captain) and Tanegashima (the swim club vice-captain); they all share an incredible obsession with money for personal reasons and want to gain enough money to fill a pool and swim in it. When Kikaijima was a child, her father left because the family was in debt, and her mother became sick from working herself in to the ground. All the people that Kikaijima had thought were friends left her because her family had no money. Kikaijima believed that "anyone would be sad if they lost their wallet, but if we died, nobody would care." Medaka corrects her by saying that if they died, she would be sad for them. Afterward, Kikaijima is recruited as the treasurer, and is the only member of the group who is paid for her job.
Voiced by: Ai Kayano