Kou and Kinji's relationship initially started off as hostile after Sun Wukong attacked Kinzou (GIII) with her compliant rod almost killing him. This caused her to runaway from an angry Kinji after their coincidental encounter at a rice porridge shop. However, after Kinji caught up to Kou and began comforting her while crying, she began to open to him by explaining she had another consciousness artificially implanted into her and could not control Sun when she attacked Kinzou. She felt bad about Sun killing Kinzou until Kinji mentioned to her happiness and relief that he was still alive. After Kinji came to understand Kou situation and showed compassion to her, she began to like him and did not want him to die including being willing to be killed by him. Also, Kou even gave an ancient Chinese salute as a sign of deep respect she has for him.
The Cao Cao sisters treat Kou similar to the way Aria treats Kinji by having her run errands for them due to Kou having a timid personality that can be taken advantage of.
Sun Wukong Edit
Sun appears to work well with the Cao Cao sisters as they teamed up to try and take down Team Baskerville in Hong Kong.
Shokatsu is Kou/Sun Wukong superior in Ranpan who controls Patra Key, which can switch Kou and Sun Wukong consciousness at will.
Sun Wukong Edit
Sun appears to despise Shokatsu for being able to control when her consciousness appears and forcing to be ordered around.
Kou was Kikuyo Ranpan connection as part of their business deal with the Kagataka Family Syndicate until the syndicate was disbanded.