Ayumu, always stuck to his side. Very clever and a quick-thinker, her confidence borders dangerously on overconfidence. She is extroverted and is Ayumu's polar opposite, serving as one of the series' few comic-relief characters. Her skill with computers are as amazing as her hacking abilities and she has access to over one hundred resources. She blackmails Wataya often, and is very fond of Ayumu's cooking (to the point where she even thinks along with Rio that she wants to become his bride). Hiyono is also one of the few who whole-heartedly believe in Ayumu; she also has a great deal of faith and loyalty in him, and is also hinted by Madoka and herself that she has some feelings for Ayumu.