High schooler Saya is a friendly amnesiac, who lives in Okinawa with her stepbrothers Kai and Riku and adoptive American father George, a retired Vietnam War vet. One night, mysterious bass violinist, Haji, saves Saya from a monster.

Haji reawakens Saya's powers, but only for a while. The military is tracking another monster.

Before George and his friend from the military, David, can reveal to Saya her full backstory, tragedy strikes.

George is in critical condition. Haji helps Saya find Kai, who's tracking down the second monster with the intent to kill it himself.

David plans a rescue mission to get George out of the military base but Kai wants to join in on the mission and he's willing to literally fight David over this.

The rescue mission to get George out of the military's hands does not go as planned.

The kids deal with their loss. David locates another facility where the monsters might be kept, this time in Vietnam.

To investigate David's lead, Saya joins the private girl school in Vietnam that might be a front for the organization that created the monsters.

Kai and Riku also arrive in Vietnam. Riku befriends a cute local village girl, who was left crippled by the mines placed during the Vietnam War that the locals dig for to sell as scrap metal.

Saya faces the school's mysterious Phantom, who triggers her suppressed memories about her past.

Saya meets a boy she likes at the school's dance, Japanese reporter investigates the school and the Phantom reappears.

David, who represents a group called the Red Shield, takes Saya and a team of specialists to the Vietnamese jungle to locate the Phantom's secret research facility and something called Diva. Saya's brothers are also kept there.

Season 1 finale. Saya and the team are ambushed by monstrous feral vampire children. Saya discovers who the boy from the party really is. The Phantom makes his final stand and shows his true form.

The Red Shield investigates mysterious scientist Ted A. Adams. Saya, Kai and Riku pay tribute to their dad and try to get life back to normal.

In an attempt to understand the supernatural events he'd recently witnessed in Vietnam, the reporter, Akihiro Okamura, contacts Kai and Saya's friends Mao and Kaori to learn more about Saya and her current whereabouts.

Saya and her friends arrive in Russia and take the Siberian Express to their next target. The vampires make sure that they have a very bumpy and bloody ride.

Haji takes Saya to a snowed in Russian village. They are taken in by a nice but strange young girl that the townsfolk fear.

David and his team track down Adams near Chernobyl and fight his monstrous son there.

Saya is betrayed by an ally, who then revels to her what Diva actually is.

Mysterious hooded figures break into the facility where the vampires are being created and kill every one of them. David and his team are suspected by the Red Shield to be in on the betrayal and are put in mandatory quarantine.

After failing to assassinate suave Solomon, one of Diva's top servants or Chevaliers, the hooded vampires go after another Chevalier - Saya's, hoping that his blood will set them free.

Haji and Saya visit an old burned down mansion. Saya learns more about her past there as well as who Haji actually is and how he came to be what he is now.

Still at the villa, Saya learns even more about her past there, this time from Solomon.

Saya faces Diva, but Diva has a hostage.

Red Shield tries to help Saya's little brother. Saya receives a new sword. Okamura and Mao are traveling by boat in hopes of locating Saya and Kai.

Riku is feeling better, but something's wrong. The hooded vampires attack Red Shield's ship to get to Saya and her friends.

Kai follows a pretty, blonde, hooded vampire girl through Paris, France and befriends her. She reveals her and her hooded friends' tragic backstory.

Okamura and Mao finally find Saya and her friends but so do the hooded vampires.

Cursed Blood: Kai deals with the loss of his friend. Okamura tries to convince David to let him join the team, while Mao tries to convince Kai.

Joel's Diary: Saya learns the rest of her backstory from the leader of the Red Shield as well as what went wrong on that fateful gory night in Vietnam 30 years before.

Breaking Shield: Saya and her family spend a nice day in town completely unaware of the vampires' plot against the Red Shield that's been set in motion.

A Boy Meets Girl: Diva's all out assault on the ship that serves as the Red Shield headquarters begins and a horrific massacre that claims even the lives of those closest to Saya ensues.

The Power of Believing: Kai and David try to recuperate after the events of the last episode. Things don't go well. The plans of the evil corporation that created the feral vampires moves to their next phase.

The World Where We Exist: The recuperation continues until a vampire breaks into the countryside house of the family with whom Kai and the others are staying.

Tomorrow Without Hope: The surviving group of the hooded vampires teams up with Saya.

Mismatched Feelings: David infiltrates Cinq Flèches, the company behind feral vampires, to capture Van Argiano, the candy-loving scientist that runs it. At an opera house, Saya faces Diva's servants James Ironside and Nathan Mahler.

To a Level of Sheer Madness: Cinq Flèches' super-soldiers led by the Phantom attack the countryside hideout of Saya and her friends.

Showdown Island: Saya, her friends and the hooded vampires go after James Ironside.

Magic Words Once More: The team must determine whether the mysterious, sophisticated power player, Amshel Goldsmith, is a friend or foe.

Dreams That Chevaliers Dream: Solomon reveals his backstory.

Place Where I Belong: The team plans their next move. Saya takes a breather and Mao has a talk with her. Goldsmith reveals his diabolical plan.

Soprano of Miracles: The characters reflect on Diva's startling pregnancy. The day ends with a showdown.

Confused Heart: After kidnapping Saya, misguided Solomon tries to charm her and convince her to be with him.

Into the Light: The hooded vampires clash over the fact that some of them want to be more like humans, while others want to embrace their vampirism.

Turn the Palm of Your Hand Toward the Sun: James Ironside and the hooded vampires engage in a brutal fight.

May Tomorrow Be a Clear Day: The team finally uncovers what the vampires' apocalyptic end game is.

Beyond All Blood: The team is on their way to stop Diva's live performance at the opera that could turn millions of people into vampires.

Skyscraper Opera: The team's plan to prevent Diva's performance fails. In desperation, they come up with plan B.

Two Queens: Saya and Diva clash for the final time.

It Will All Work Out: Saya must decide the fate of Diva's children. Goldsmith returns for one final showdown. The show ends on somewhat of a somber note.