Visual novel version
The new heroine and the young queen of the kingdom of Shu in the sequel, Shin Koihime Muso. Being quite young she is naive, often reluctant to go to war, and hates paperwork (much to the chargin of Kan'u who as a result often scolds the young queen and reminds her of her duties), but has a lot of confidence on her subordinates. She falls in love with Kazuto, causing Kan'u to feel a bit of jealousy.
Anime version
Introduced in Shin Koihime Muso. A descendant of a distinguished family who was given possession of a sword, the family heirloom, before she encountered the man who would eventually steal her name (leading everyone to believe him to be Ryubi Gentoku in the first season) and her sword, causing her to fall into disgrace. To redeem herself, she ventures out in search for the man and her sword, which leads her to Kan'u and company, who are greatly surprised of her identity (in fact she is nearly assaulted by Kochu, and later Bacho, upon hearing of hearing of the name Ryubi again). After being attacked twice by bandits (and almost being raped in the second attack) while venturing alone, she concedes to Choun's suggestion of joining their group for protection. She is revealed to be an old classmate of Kosonsan in primary school, even though she doesn't remember Kosonsan's real name Pairen much to the latter's disgust.
She eventually gets her sword returned to her from Enjitsu, thanks to Shokatsuryo who conned Enjitsu with a "mysterious container", in the same fashion Enjitsu herself obtained the sword from Ensho. Sadly, she loses her sword again in an effort to help defend a village from an army of attacking bandits. However, she realize her bravery to sacrifice her sword to defend the village after a lecture from Kan'u so she decides to follow her example by making a vow of sisterhood as her younger sister but Chohi was against it as Chohi was already her younger sister so instead she becomes Kan'u older sister. By the third season, she, Kan'u and Chohi have accepted calling each other sisters. Also to her surprise, she is given a new sword, claimed by the Touka villagers to be a "sword left by the gods".
(wikipedia.org)