Shuuko is a very shy young girl, who operates the net navi Aquaman. She lives with her two brothers Taichi and Atsuho, who happen to be twins. Her parents died when she was young, and she has been blaming herself for her misfortune ever since. This attitude has caused her self confidence to crumble, which affects the personality of her cute net navi as well.

Poor Shuuko also has a reputation as "the bad luck girl", as unfortunate things happen wherever she goes. Therefor when Netto and the others meet her, they are very aprehensive. Higure eventually helps turn her spirit around, and re-awakens her self determination when Aquaman is in trouble. After these events, Shuuko sticks around to work at Higureya.