The Shinsengumi have established their new headquarters in Edo. Hijikata has been working nonstop since their arrival as the temporary leader of the Shinsengumi in Kondo's absence, causing Chizuru and the squad a great deal of concern. In addition to working all night for several consecutive days, Hijikata is also struggling to control the urges to drink blood caused by his new Rasetsu powers. Kondo returns to the Shinsengumi headquarters and informs the squad that they are being renamed the Kouyou Chinbutai. Acting under the orders of the emperor, they will be attempting to defend Koufu Castle from pro-imperialist factions. The Shinsengumi captains aren’t happy with how the Tokugawa shogunate appears to be yielding to the Imperial faction and Nagakura is very upset and distrusting of Kondou’s daimyo aspirations.

Okita's tuberculosis is getting worse, and Hijikata refuses to let him accompany the rest, telling him to get better first. The troops leave Kondou in Hino, and proceed on. Nagakura shows disagreement with Kondou's actions, and Saito asks Hijikata if he think that they can win the battle. Hijikata replies that in their current state, they cannot match the enemy. Later, Chizuru has a nightmare and follows Saito outside the camp, where he tells her about his past and his opinions. They meet up a messenger, who tells them that the enemy has already entered Koufu Castle. Kondou refuses to let the army retreat, and Hijikata leaves to find more troops. Before he leaves, he makes a "Chiming Metal" oath with Chizuru, making her promise to stay alive and protect Kondou. Meanwhile, Kaoru talks to a mysterious man. The war starts just a few hours after Hijikata leaves, and Kondou agrees to forfeit after seeing the many men he let die in vain. Nagakura and Harada run into the Oni from before, and battle a strange group of Rasetsu. It is revealed that the creator of the Rasetsu is Chizuru's father, Koudou.

Shiranui, Harada, and Nagakura fight the Rasetsu, but there are too many of them. Shiranui uses his last bullet to blow up a cart of explosive material, allowing the Shinsengumi to escape. Kondou and Chizuru escape into the forest, but are confronted by Kaoru, who reveals his relationship to Chizuru. Chizuru refuses his offer to leave with him, and draws her sword against him which shocks Kaoru. She is almost killed by Kaoru but Okita interrupts him. He tries to defeat Kaoru, but fails. Kazama appears and kills Kaoru. The Shinsengumi moves into residences at Hatamoto, and Harada takes Chizuru out to eat dango, and they bring some back for Okita. Hijikata comes back to Edo with new troops, and Harada and Nagakura leave the Shinsengumi to fight the Satsuma and Choushuu in their own way.

Saito follows Sannan out at night, but loses him when he sees Amagiri killing a Rasetsu. In return for helping him kill the Rasetsu, Amagiri tells him a shocking secret about the Rasetsu. Saito relays this information to the Shinsengumi, and Hijikata orders Sannan to stop all experimentation on the Rasetsu Unit. They also decide to move to Aizu. Chizuru witnesses Hijikata having a vampiric impulse, but Hijikata refuses to let her give him some of her blood. Later, after the Shinsengumi make camp in Aizu, the enemy decides to attack the headquarters when all of the troops are out for training. Kondou orders Hijikata and the rest to escape while he stays behind. As they escape, they run into enemy soldiers. Despite Chizuru's plea, Hijikata uses his Rasetsu powers and kills them all. Kondou peacefully surrenders to the enemy, and Hijikata angrily laments his choice to leave Kondou behind.

The Shinsengumi join up with the old Bakufu army and head for Aizu. Hijikata desperately petitions to spare Kondou's life, but his pleas fall on deaf ears. Back in Edo, Harada meets up with Shiranui, and decides to repay his debt to him. Ootori Keisuke, the commander-in-chief, introduces himself to Hijikata and asks him to become the adviser for the vanguard. Hijikata has another vampiric impulse, and drinks Chizuru's blood. The Old Bakufu army attack Utsunomiya Castle, and Hijikata faces Kazama once more, transforming into his Rasetsu form. But he is wounded by Kazama's demon-slaying sword and stays behind Nikkou to receive medical treatment. Ootori tells him that his performance as an adviser was a failure, and Hijikata recalls Yamazaki's words before he died. Nagakura comes to visit them before he leaves for Aizu.

Okita gets angry at Hijikata, who failed to rescue Kondou before he was beheaded. Saito forces Hijikata to stay behind and rest while he takes the front line. The New Government Army attacks the Shougitai, and Harada and Shiranui run into Koudou and a group of Rasetsu coming to seek blood. The two of them manage to kill all of the Rasetsu with silver bullets, but Harada is mortally wounded. Just as Koudou is about to kill Shiranui with a bomb, Harada throws his spear at him, making the bomb backfire on Koudou. Harada and Shiranui are never seen again by the Shinsengumi. Okita overhears some men planning to assassinate Hijikata, and uses his Rasetsu powers to kill them all. Hijikata hears rumor of a white-haired man fighting dozens of men, and he and Chizuru run to the place where Okita is fighting. By the time they reach there, the only thing left is Okita's sword, Okita himself having used up all of his lifespan and disintegrated.

Saito leads the Shinsengumi into the Battle in Aizu. He is sent to command Masaki, a young Aizu Clan soldier, and his men. Masaki refuses to obey his orders, believing that Saito is not a warrior since he wears his swords and clothes differently. The Shinsengumi and Masaki's army attack at Shirakawa-guchi, but are forced to retreat. Later, Masaki acknowledges Saito's status as a warrior. Hijikata recovers enough to return to the Shinsengumi. They decide to attack at Bonari Pass, and again they are completely outnumbered. Masaki sacrifices himself so Saito and the Shinsengumi can retreat. The lord of the Aizu orders them to retreat to Sendai to get reinforcements while he stays behind. Saito decides to stay with the Aizu Clan and fly the Shinsengumi's banner.

Hijikata meets up with an admiral in Sendai, who mentions that murders have been happening frequently outside the castle. He believes that maybe they have a strange unit, which Hijikata and Chizuru suspect to be the Rasetsu Unit. Shortly afterward, Heisuke shows up and reveals that Sannan has most likely joined Koudou, who is still alive. However, Koudou shows up with his Rasetsu unit and kidnaps Chizuru, leaving Heisuke fighting alone in the broad daylight. Koudou attempts to persuade Chizuru to lead the Rasetsu in order to rebuild the Yukimura Clan, but she refuses, saying that human and Oni lives are equal. Just as Heisuke and Hijikata appear, Sannan claims that he indeed was working with Koudou to build an empire that Rasetsu and Oni could live peacefully. But he reveals that he was actually spying on Koudou. Hijikata, Heisuke, and Sannan fight the Rasetsu, and Koudou is killed protecting Chizuru. Heisuke and Sannan crumble to dust after they have used all of their lifespan. The Shinsengumi makes plans to move to Ezo, and Hijikata orders that Chizuru stays behind in Sendai while he goes to fight.

Hijikata and his army manage to capture the city the Matsumae Clan is guarded by. However, they lose their battleship, The Kaiyo Maru. During a meeting, Hijikata experiences blood thirst, and has a hallucination of Chizuru. Back in Sendai, Chizuru visits Koudou's grave on a daily basis, but finds Kazama Chikage there one day. Chizuru believes that he has stopped going after Hijikata, but Kazama swears not to go back on his promise to fight Hijikata once more. The Republic of Ezo is found, and Hijikata is elected as the Vice Commissioner, putting him under more pressure. Ootori secretly sends for Chizuru to work as Hijikata's attendant. The Republic of Ezo attempts to attack the enemy once more at sea, but they only have one ship, having lost the others in the bad weather. They are forced to retreat, and Hijikata tries to get Chizuru to leave. She refuses and promises to stay with him to the end.