The story focuses on the main character Sayori, who is a modern high school girl. She finds a mysterious pendant while out helping with an archeological dig (she's in the high school history club, and so is forced to attend), and later has a strange dream - it seems that the scene is from about a hundred and fifty years ago, during the last days of the samurai, and she sees Hatsuhime, princess of the Mochizuke clan, assassinated! It gets even more strange when the scene changes, and Sayori realizes that she's in Hatsuhime's body; that she has somehow seen how things were, and the situation has somehow "reset", giving her the chance to avert the princess's terrible fate.
Tsukuba Muneshige (筑波宗重?) - Hatsuhime's servant, and loyal samurai and clan vassal. He has a penchant for making terrible jokes and bad impressions, which he sometimes uses to try to cheer Hatsuhime/Sayori up. Unfortunately, his impressions can get himself into trouble, as well.</li>
'(Yo)Shiranui Yoza'burō (不知火 用三郎?) - usually just called Yo. He is one of the bodyguards hired to save Hatsuhime, and is the youngest of the group. He resents being treated like a child, and is from a ninja family.</li>
(Jin) Murasame Jinnosuke (村雨 心ノ介?) - a fiery character with red hair and something of a rough - but good natured - temperament, he's one of the bodyguards hired to save Hatsuhime. He is also the first of such bodyguards you meet, as Hatsuhime bumps right into him at the festival, before the conspiracy and assassination attempt. He is exceptionally awkward around women.</li>
(Bo) Tsubaki Tainojō (椿木 泰之丞?) - his nickname "Bo" comes from an alternate way to read "Tsubaki". He is rather androgynous (bishōnen, actually), and is from a samurai family. He seems rather elegant, and is interested in the paranormal.</li>
(Mon-Mon) Kadokura Monzan (モンモン(門倉紋山)?) - a Buddhist priest, who seems to like the company of women. He is very strong, however, and knows many things and has even medical knowledge to the extent that he can stitch a wound back together perfectly. He gives himself the nickname "Mon-Mon", and tries to sound cute. This usually means he isn't taken seriously.</li>
Tatsunami Ittousai (辰波一刀斎?) - a suspicious person who wears glasses all the time; he is hired as a bodyguard but is seen by the others as nothing but an assassin or a sociopath. He also has a body covered with scars from old sword wounds. Apparently, Jin has also tried to kill him before, but Ittousai survived the attempt. He also wears his glasses even when bathing.</li>