An e-mail containing the words "Make a pilgrimage for the past with me", accompanied by a strangely familiar tune, lure professional hitwoman Mireille Bouquet into meeting with Kirika Yumura, a Japanese amnesiac with amazing killing skills. Could the mysteries of Kirika's lost memories shed some light on Mireille's own past?

Having gone into business as Noir, Mireille and Kirika take on their first job together- the assassination of a far right terrorist and his collaborator in the Peace Department.

It seems like a simple job for Noir when they are hired by a widow to take revenge on her husband's killer. But when the job turns out to be a set-up, the tables are turned, and the hunters become the hunted. Can Kirika and Mireille hope to out-think their enemies and escape with their lives?

Mr Hammond is a man of many roles- on the one hand, he is president of the nefarious Atride Corporation, well known for inciting wars to make a profit, but on the other, he is a father adored by his teenage daughter Rosalie. And now, in sunny Ulgia, Hammond has another role- as Noir's next target. Yet there are still enemies in the shadows who want nothing more than for Noir to fail.

Having asked her old friend Vanel to find information on the people who are trying to kill Noir, Mireille is shocked to discover that whatever he has uncovered has cost the lives of him and his entire family. Realising that Vanel must have been onto something important, Mireille begins her own investigation to find out the secret that cost her friend his life.

During the Cold War, a KGB agent named Yuri Nazarov ordered the slaughter of members of an ethnic minority known as the Tashkil. Now the few surviving Tashkil have commissioned Noir to avenge those deaths by killing Nazarov. Yet these days Nazarov is a benevolent old man who has dedicated himself to helping the destitute. Can Noir bring themselves kill Nazarov given his apparent change for the better?

Noir has just fulfilled a contract to kill a revolutionary leader, but Kirika is shot herself whilst making the hit. With the remaining revolutionaries hot on Noir's trail and out for revenge, Mireille realises that her only chance of escaping may be to relieve herself of the burden of her injured partner.

In exchange for a document that has a connection with the mysterious Soldats, Mireille and Kirika assassinate a Mafia Don. But the Mafia is well known for its revenge policies, and Noir soon find themselves the target of the ruthless Mafia princess known as the Intoccabile, a woman who Mireille has met long ago, and has cause to fear.

Noir and the Intoccabile still have unfinished business with each other after their last face off, and each side knows that matters can only be resolved with a final showdown. To that end, both sides travel to Sicily, where Mireille and the Intoccabile met as children. But with Kirika's arm injured and Mireille fearful and doubtful about her ability to defeat the Intoccabile, does Noir have any hope of victory? And will Mireille and the Intoccabile's past play a part in the coming encounter?

Kirika and Mireille are in for a surprise when they find that another professional has already taken out their next target. Word on the streets is that Noir was the killer- do the rumours refer Kirika and Mireille, or is someone else using the same code name?

Mireille and Kirika are contacted by a man within the Soldats who is willing to give them a book containing valuable information. As the two women follow up this intriguing lead, they once again come up against the "true Noir", the mysterious assassin Chloe.

The mysterious Chloe has one last mission to carry out before she goes home to Altena and the manor- she has been ordered to kill an old NATO intelligence officer. As she journeys to Switzerland to carry out her task, Chloe finds that she is not the only one who has been sent to kill Reimann, and that she may have to protect him if she wants to be the one to eventually take him out.

When Kirika begins spending all her time down at the river in the company of a young painter, Mireille warns her not to get too close- after all, relationships aren't something you can pursue easily when you're in their line of work. Mireille has problems of her own, however- an old job comes back to haunt her when one of the survivors decides to put together his own mission of revenge.

Ten years ago, Mireille left Corsica with her uncle Claude, who looked after her and trained her as an assassin. Now, Claude has returned to Paris, but Mireille's delight at seeing her uncle again is tinged with doubt. An assassin of Claude's calibre is bound to have secrets of his own- secrets that could spell trouble for Noir.

Mireille and Kirika are offered a job in Taiwan- and their employer is none other than the Soldats. Despite the danger, Noir decide to accept, hoping that working for the Soldats will help them uncover some answers. But the assignment proves to be far from straightforward when they find themselves targeted by the Taiwanese assassin Shaoli, better known as the "Cold-Blooded Killer".

Kirika and Mireille's mission to destroy the Hang Yiban triad went awry when the Hang Yiban sent their own assassin- the ruthless Shaoli, to destroy Noir. Now, Mireille has been captured by the Hang Yiban, and Kirika must work with the mysterious Chloe to free her. But even if Mireille can be rescued, Noir still has the job of eliminating both the Hang Yiban leaders, and Shaoli herself.

It has been a decade since Mireile was forced to flee from Corsica after the murder of her family, and she has always been too afraid to return- until now. Determined to uncover the truth about her parents' murder and its connection to the Soldats, Mireille returns to her childhood home. But as she tries to stir up information from the past, she attracts the attention of those who would rather it remained buried.

Still upset over the truths she learned in Corsica, Mireille wants nothing more than to be alone, and sends Kirika away for a while. Wandering the streets on her own, Kirika is approached by a faction of the Soldats, promising to supply information. But if Kirika follows this lead, she will be leaving Mireille alone- and vulnerable.

Mireille and Kirika continue to chase leads that might help them locate a copy of the manuscript about the Soldats, unaware that the danger is greater than ever. For the Soldats council is fed up with playing Altena's games in which Kirika and Mireille are given "trials", and decide that now is the time to finish them off, once and for all.

Two maidens loyal to the Soldats, tested through trial, and appointed by ancient ritual- this is the true nature of Noir. As Altena recounts the history of the Soldats, the Council itself plots to move against her, and her idea of recreating Noir. Meanwhile, Chloe eagerly awaits as Kirika faces one last trial, hoping that the two of them will indeed prove worthy to become the next incarnation of the true Noir.

For Kirika and Mireille, the point of no return has been reached. For, as Kirika's memories come flooding back, Chloe unravels the mysteries of the past for Mireille, revealing the true identity of her parents' murderer. When they first met, Mireille promised that she would kill Kirika once they discovered the truth, but now that the time has seemingly come, will she keep her word?

Kirika and Mireille's partnership has come to an end, and with no place to return to, Kirika finds herself wandering through the wilderness. Found and rescued, she is taken to what seems like a simple country village. Yet when Kirika realises that all the villagers not only recognise her, but have been expecting her arrival, it becomes clear that all is not as it seems.

Kirika and Chloe are in Altena's hands now, but the Soldats who oppose her have one last card to play- they can try to recruit Mireille. If Mireille accepts, then she will have to infiltrate the manor and take her place as one half of Noir by killing either Chloe or Kirika. And if she refuses, then the Soldats will have no choice but to kill her. Can Mireille find a way out the deal, or is she fated to become the tool of the Soldats?

Drawn by her instincts and buried memories of the past, Kirika finally rejoins Chloe and Altena at the manor. Whilst a delighted Chloe shows Kirika around, and tries to help her recall their shared childhood, Altena begins gathering together everything she needs for the final ritual that will confirm the two women as the next incarnation of Noir.

Only two maidens can serve as Noir, but now that Mireille has arrived at the manor, all three candidates are present- and one must lose out. Will Chloe and Kirika pull together to remove the "outsider" from contention, or will Mireille find a way to get through to her former partner? Only a heated conflict in the manr grounds themselves can decide the answer.