Yu and Mika are finally reunited, but the injuries Mika had sustained from fighting the Demon Company threatens his life. Determined to keep Mika alive, Yu tries to persuade Mika into drinking his blood... Even if it means Mika will become a true vampire.

Thanks to his "experimentation," Yu makes a miraculous recovery and once again, goes back to save Guren. Pushing too hard, Yu nearly becomes a demon, but Kimizuki stops him by force. The squad carries Yu out and heads for safety, but then encounters Mika.

The Shinoa squad re-learns the hard cold fact that it's very possible to lose comrades, but there's no time to mourn. They must move on to go rescue the hostages. Right after their departure, Mika and the other vampires arrive to Nagoya as well.

Yūichirō and Shinoa get separated from the others and after taking a wounded soldier to be treated, they regroup to assist Guren's party. In the occasion, Yūichirō and Mikaela finally meet again.

The Shinoa squad and Narumi squad join forces to carry out their mission - to kill the Fifteenth Progenitor, Lucal Wesker. While they succeed in their mission without losing anybody, others were not so lucky. Nine teams fail and were taken as hostages...

Mikaela attempts to escape, taking Yūichirō with him. However, seeing his friends at the mercy of the vampires, Yūichirō goes out of control when a dreadful power emerges from him, threatening allies and foes alike. Shinoa manages to stop him but he falls unconscious.

The survivors of the Moon Demon Company get to the rendezvous point, only to find out that their orders are to "standby." Enraged, they decide to ignore the orders to save Guren, when Kureto appears. Apparently, Kureto has something else on the agenda.

Four years after escaping, Yūichirō is part of the Japanese Army and is eager to become a member of their special vampire hunting force, the Moon Demon Company, but his reckless behavior leads him to be suspended, until a vampire attacks the local school prompting him to face the enemy against orders.

Instead of dying with the rest of his friends, Yūichirō's best friend Mikaela was transformed into a vampire by Krul Tepes, the queen of the vampires and now works as her aide. Meanwhile, Yūichirō finally begins his training to become a member of the Moon Demon Company.

Wary of the Human Army's rise to power, Krul calls the vampires to war against them, while Yūichirō and his friends are finally selected to attempt to claim a demon weapon for themselves, despite knowing the risks.

After passing the final test, Yūichirō and his classmate Shihō Kimizuki obtain their own Demon Weapons, but when Yūichirō's friend Yoichi Saotome ends up possessed by his weapon, the duo must find a way to bring him back to his senses without killing him.

When the Shinoa squad arrives late, they realize just how serious this mission is for Guren. Knowing this is an impossible mission where many will die, Guren puts his emotions aside and orders his men to not necessarily survive, but to win.

Yūichirō and his companions arrive at Shinjuku to help repel the vampire offensive, while Guren's party spots Mikaela and Ferid, and decides to face them.

Yūichirō learns that one of his schoolmates was possessed by a demon and decides to confront him not only in order to save him but to make a contract with the demon and obtain his power. However, he soon learns that subduing the demon will not be such an easy feat.