Chizuru is the main protagonist. She came to Kyoto in search of her missing father, a Dutch-educated doctor who, on orders from the Shogunate, developed the "ochimizu", a potion which increases the drinker's healing abilities, speed, and strength but which also has an unfortunate side-effect of turning the drinker into a mindless, vampire-like monster called a rasetsu.
Hijikata is the vice-captain of the Shinsengumi and makes most of the Shinsengumi's decisions. He is the one who brought Chizuru back to Shinsengumi headquarters. He has taken on the responsibility for Chizuru's welfare and acts as if he's dismayed at having to do so, but in reality he does care for Chizuru's safety and is often shown protecting her during battles.
Okita is the First Unit Captain of the Shinsengumi. He is a brilliant swordsman, but he suffers from tuberculosis. He is based on the historical Okita Sōji.
Kondou is the commander of the Shinsengumi. He has the trust, respect, and loyalty of his men inspite of being very emotional. He is based on the historical Isami Kondō.
Yamanami is the bespectacled scholar captain of the Shinsengumi. In spite of being a ruthless tactician, he is kind and caring albeit a little reserved. He is based on the historical Yamanami Keisuke.
Shinpachi is the Second Division captain of the Shinsengumi. He is usually very cheerful, especially when he is with his comrades. He is very skilled with the sword, but he is also a true alcoholic and womanizer. He is based on the historical Nagakura Shinpachi.
Harada is the Tenth Unit Captain of the Shinsengumi. He prefers the spear to the sword, but he is seen carrying both. He is based on the historical Harada Sanosuke.
Heisuke is the youngest member of the Shinsengumi being around the same age as Chizuru. He is based on the historical Tōdō Heisuke.
Saito is the leader of the third squad of the Shinsengumi and a master of the left hand sword technique. He is silent and a taciturn but also very loyal, polite, and wise. He often analyzes the situation before attacking to figure out which actions are necessary to complete the mission. He is based on the historical Saitō Hajime.
Kazama is a member of the Bakumatsu, enemies of the Shinsengumi. He is the strongest Oni in the North and is after Chizuru so they can mate and create stronger oni.
