Wilk (ウイルク, Uiruku) was Asirpa's father.
Wilk has a scar that runs horizontically across his forehead and down his left eye to the cheek which he received from being in close proximity to an explosion.
Wilk can be brutally violent when necessary as seen while interrogating an Okhranka officer. In this regards, he was once compared to Toshimichi Okubo, who was described as being cold-blooded due to the fact that he was willing to use any means necessary in pursuit of his goals.
Wilk was born in a Karafuto Ainu village, where his mother and maternal grandparents were born as well. He was the son of a Polish father and a Karafuto Ainu mother and raised as a Christian. In 1875, when the Treaty of Saint Petersburg was signed by both Japan and Russia, Karafuto became a Russian territory but many Ainu in Wilk's village were allowed to leave to become Japanese residents. Since Wilk's father was Polish, Wilk was unable to leave Karafuto as well, and so stayed in the village alongside his parents.
Sometime during his youth, Wilk took down his very first prey, a musk deer, and cut his hohciri off on the spot as a sign of adulthood. Wilk, alongside Kiroranke wandered all over Karafuto during their younger days and together became known as "muskies". Wilk also shot and killed a reindeer that had belonged to another person, so he joined their wild reindeer hunt party as an apology. Wilk and Kiroranke had also hunted a lynx and they sold the pelt for a lot of money. They cooked its meat in an attempt to eat it, but Wilk did not like the taste of it, making a disgusted face.
As a young man, Wilk was involved with a group in Russia known as the People's Will and became closely acquainted with their leader, Sofia Golden Hand. One day in Saint Petersburg, a teenaged Kiroranke failed to throw a bag of bombs into the Russian emperor, Alexander II's carriage. Wilk hurriedly ran and picked the bag up, managing to throw it into the emperor's carriage as the emperor stared at him in shock. The ensuing explosion killed the emperor, and damaged Wilk's face as he was carried away by Kiroranke.
As he spent time with Sofia, Wilk described to her about the Ainu culture and their way of living, stating that if they don't fight to protect them, they will lose them and that the children born in the future will never know about their heritage. He laments that the indigenous people of America lost to the white men because they were in constant conflict and being too busy killing each other. Wilk then tells Sofia about the Ainu in Hokkaido and expresses his dream of creating a far eastern federation that would include both Karafuto and Hokkaido.
For over ten years since the asssassination of Alexander II, Wilk, Kiroranke, and Sofia led their lives as fugitives until they arrived in Vladivostok and hid in a farmhouse there. There, they went to meet a Japanese man named Kouichi Hasegawa and asked him to teach them Japanese, promising to pay him for the troubles. Wilk and Kiroranke were able to learn Japanese quickly, much to Hasegawa's amazement. The two of them also took Hasegawa out and taught him how to catch some martens with some traps and Hasegawa is pleased that he will be able to sell the pelts to buy a new camera. However, Hasegawa expressed concerns about their background, especially Sofia's and asked them where they came from.
Later, as Hasegawa prepares to take the revolutionaries's picture, he begins to talk about the Three Great Nobles of the Restoration. Afterwards, Wilk and Kiroranke discusses crossing over to Japan and Kiroranke mentions that Sofia is feeling conflicted but says that if Wilk tells her to come with them, she will. When they arrived at Hasegawa's store for their lesson, he tells them not to come anymore and that they should leave right away. Just then, they hear a knock at the door, which Hasegawa opens to see a Russian officer. Wilk recognizes the officer as being a part of Okhrana, a secret police force that cracks down on revolutionaries and anti-government elements.
Sofia attacks the officer with the butt of her rifle, which gave Kiroranke an opportunity to bring him inside for Wilk to interrogate. The officer does not know who they are, and that they only came for the Japanese man, Hasegawa, who is revealed to be a spy for the Japanese army. A gunfight erupts between the revolutionaries and the Okhrana as Wilk held the officer hostage. Kiroranke uses a machine gun that Hasegawa shows to him to mow down the officers, however one is able to survive. Wilk exclaims that not one of them should be allowed to escape, lest he comes back with reinforcements. In response, Sofia heads out and manages to kill the lone survivor.
The revolutionaries and Hasegawa finds that Hasegawa's wife and daughter, Fina and Olga had been caught up in the battle and upon examining Fina, Hasegawa says that she cannot be saved. As Wilk notices his own bounty lying on the ground, Hasegawa tells them to hurry up and leave and Wilk takes a crying Sofia by her arm. Wilk analyzes the situation, saying that no port is safe for them, which meant that entering Japan will be difficult. He then suggests that they should head north where they would be able to cross over the drift ice and into Karafuto. As Wilk states they should head to Hokkaido to confirm the special information leak, he notices Sofia hesitating behind him. Sofia professes her love to Wilk but says that she cannot go with him since she cannot get Olga's death out of her mind. She swears that she does not need happiness as a woman and that she will continue to fight as a revolutionary. Hearing this, Wilk says his farewells to Sofia as he and Kiroranke heads over to Japan.
In Hokkaido, Wilk meets Inkarmat, who taught him about the land and Ainu culture. After settling down in Otaru, he married an Ainu woman and they had a daughter, Asirpa. Wilk's wife died shortly after Asirpa's birth. Wilk taught his daughter to hunt with the hope of preparing her to lead an Ainu independence movement. When Asirpa was a very young child, Wilk gave her his own hohciri and told her that when she gets bigger, they will go on a hunt and until then, she must keep it tied into the front of her hair.
Sometime later, when Asirpa became a young girl, sitting at a campfire in a small hut, she asked her father about her mother. Wilk claimed that she was a beautiful woman like her and talked about how they met. He says that Asirpa would be the one to lead the Ainu people and that he has something to tell her which she must never forget. Wilk once told Asirpa about a meko oyasi, saying that it was a monster cat that would eat a person's shoes, clothes, bags, and carrying ropes. Asirpa found the story to be frightening and asked if it even ate the tobacco case.
Wilk was arrested trying to transport some of the gold that had been stolen from Ainu who were preparing to fight the Japanese. His face was heavily disfigured at the time, so, with his identity being unknown to authorities, he was named "Noppera-Bou". Among the Ainu, he was presumed to be killed among the other men guarding the gold. Wilk would deny being the one who killed the men guarding the gold.
Wilk is killed during Sugimoto's Group's break in into Abashiri Prison.
The name "Noppera-Bou" derives from a Japanese youkai.