Aika is part of the Ikebana Club (Floral Design Club in dub) at Heartland Academy.
After being brainwashed by Girag, she invited Yuma Tsukumo, the Numbers Club, and Rio Kamishiro to her club where she displayed a dislike for the "worthless" parts of flowers, cutting them up. She initially planned to duel Yuma for his "Numbers" and hypnotized his friends into sleep, though Rei Shingetsu sensed that something was wrong and only pretended to succumb to the hypnosis, and Rio saw through Aika's scheme and challenged her to a duel instead. During the duel, Aika was cynical and overconfident, subtly insulting and criticizing her opponent on every move she made. After putting up a tough fight, Rio defeated Aika, returning her to normal, although she didn't remember anything she had done while being brainwashed.
After the Barians' attack, Aika and her club were seen arranging flowers for the Heartland Academy Fun Fair. She talked to Takashi and told him that she liked his serious nature.