Anime
Kan'u is known as the Beautiful Black-haired bandit fighter and wields the Green Dragon Crescent Blade. She is much like her male counterpart, Guan Yu. She is also one of the main characters beside Chouhi. Her past reveals that her family was killed by bandits, which made it her quest to ensure Innocent people will never suffer like she did. She cares a lot for her friends, and she is a sister to Chouhi after they swore a vow of sisterhood because she felt sorry for Chouhi's loneliness. Two common recurring jokes about her are:

1) That most people who heard of her believe that she is a beautiful girl, only to meet her and realize that she is just normal-looking, and

2) Some of the female characters mistakenly believe she and Rinrin are mother and daughter despite the fact she is still young.

The second running gag is carried even further in Shin Koihime Musou when Kousonsan mistakes Koumei as Kan'u's daughter as well. Somewhat self-conscious of her appearance, she often finds herself as the butt of jokes to those who blatantly point out physical aspects of her, such as her age, which she is very sensitive of. Another notable gag was when Kan'u found a seemingly-suitable male soulmate, the relationship was to be very short-lived. She is a pure virgin, as noted in season 1's fourth episode, where she nervously admits to Karin that it was her first time when she conceded to sleep with the young ruler in exchange for Bachou's release. After having Ryuubi join them in the second season, she becomes a role model for Ryuubi who later decides to makes a vow of sisterhood with her as Kan'u's older sister (as Kan'u already made vow with Chouhi's as her older sister). Kan'u at first felt it was inappropriate as she is older than her but by the beginning of third season, she accepted calling Ryuubi her Aneue (older sister).

Visual Novel
Arguably the main heroine of the first game. Kan'u shows up shortly after Hongo is transported back in time and saves him from a group of bandits, and due to Hongo's costume and manner of speech, subsequently mistakes him to be the "Messenger from Heaven" and becomes the first person to vow her loyalty to him. Kan'u remains the driving force behind the Hongou/Shu army and displays many heroic actions in the war, often being the leading voices for the other girls as well as the motivator of the group. However, due to her past, she strongly rejects Hongo for calling her a girl, stating, "Nothing as weak as that!"

In the sequel, Shin Koihime Musou, Kan'u is relegated to the position of Ryuubi's second in command and confidante. Here she is a very strict general and disciplinarian, especially towards Ryuubi herself (due to Ryuubi being a rather naive and reluctant queen), and Kazuto (likely out of jealousy over Ryuubi's closeness to Kazuto, since she herself in fact harbors romantic feelings toward him).

(Source: Wikipedia)