One of the most passionate of the female protagonists, and even though a very powerful leader figure just like her older brother. Despite not actually being trained in the traditional martial arts, she is a one of the strongest and most skilled now living Master Samurai of all Japan.
Sen is a very attractive young woman with a pleasant figure and long light brown hair that goes far over her back. She is most of the time seen in the series wearing a traditional school uniform for girls, that is divided in two separate and different colours, with a white skirt and long black stockings that has a small bright orange stripe at the top. As in her Master Samurai form she wears a purple kimono with two shogi pieces on each side of her hair while she retains wearing a white skirt with black stockings. Sen is almost as long as Muneakira, and seems to have feelings for him but acts very much like a tsundere towards him. Unlike most of the other girls in Muneakira's group of Master Samurai, Sen has purple eyes. Beside the great difference between the girls, all of them are very attracted to Muneakira, and then mostly princess Sen, which almost every time can end in hard hassles about who have the greatest right to be at his side.
Sen is a self-proclaimed spoiled princess and always seeks to get her way regarding any decision she wants to make. She gets extremely jealous of any girl who tries to get close to Muneakira, and generally acts upon this jealousy by flying into a rage. But despite all of this, she has been deeply in love with him since they were just children and wants to be with him more than anyone else in the group. She is also, in similiarity to her brother Yoshihiko, a very charismatic representant for the people of Great Japan when Yoshihiko is on travels outside the country.