The main character in the series, Suiryuuken or Shūyu Koukin, is a cousin to Goei and Sonken Bundai. She has long red hair, green eyes, and is not particularly intelligent but incredibly powerful. Despite her lack of interest in politics, Hakufu is fiercely protective of her friends and family. Recently, she has taken on a leadership role due to the increasing danger around her.
Hakufu possesses an exceptional ability to predict enemy movements by sensing the flow of chi or energy around them. This talent often makes her seem smarter than she actually is. She also inherited knowledge of chi magic from Master Chouchou, which she uses instinctively despite being unaware of it. Hakufu healed Koukin after stabbing him and removing evil chi from his body using this magical power.
Hakufu is also the guardian of a powerful dragon, one of the Three Great Rulers.