Asirpa is a young Ainu huntress who serves as a central figure in the narrative. Her background is deeply rooted in the traditions of the Ainu people, an indigenous group of Hokkaido, Japan. As a child, she was trained by her father, Wilk, in the skills of hunting and survival. Following his death, she experienced a period of isolation and rarely smiled, finding companionship primarily with a wolf named Retar. This period of loss instilled in her a lingering fear of being abandoned, a vulnerability that remains with her even as she forges new bonds.

In terms of personality, Asirpa is an independent, pragmatic, and capable individual, wise beyond her years due to her intimate knowledge of the harsh wilderness. She understands that nature is cruel and that weakness often leads to death, approaching survival and hunting with a serious and mature demeanor. Despite this, she has a playful, cheerful, and sometimes mischievous side that emerges when she is with friends and family. She enjoys cooking, is enthusiastic about hunting, and likes to tease her companions, particularly Sugimoto and Shiraishi. While deeply respectful of the natural world and Ainu customs that honor animals as gods, she considers herself a modern Ainu woman and dismisses certain traditions, such as tattooing her mouth or believing in fortune-telling.

Asirpa's primary motivation evolves over the course of her journey. Initially, she is driven by a desire to solve the mystery of her father's murder. However, as she learns more about the world and the threats facing her people, her goal expands. Her journey to Karafuto and the revelations she encounters there lead her to decide to find the hidden gold to ensure that the Ainu people and their culture will never be erased or forgotten. She operates on a strict moral code, refusing to kill other humans even when her own life is at stake, a principle that distinguishes her from many other characters in the story.

Her role in the story is that of a deuteragonist and an essential partner to the veteran Sugimoto. As a native of Hokkaido, her profound knowledge of the land, its flora and fauna, and the Ainu language and customs is indispensable for navigating the wilderness and deciphering the clues to the hidden treasure. She acts as a guide and a moral compass, and her survival skills frequently prove vital.

Key relationships define her journey. Her most important relationship is with Sugimoto, whom she saves and partners with. He helps her regain her smile and confronts her fear of abandonment, and she refers to him as her irreplaceable partner. She also develops a close friendship with the escape artist Shiraishi, often teasing him alongside Sugimoto. She has a complex and adversarial dynamic with the sniper Ogata, acting as his foil in many ways.

Throughout the story, Asirpa undergoes significant development. She transitions from a withdrawn and somber child to a more expressive and hopeful young woman, largely due to the friendships she forms. She matures from seeking personal vengeance to shouldering the larger responsibility of preserving her ancestral culture for future generations.

Asirpa possesses a wide array of notable abilities, all stemming from her upbringing as a huntress. She is an expert archer and is skilled in trapping, tracking, and skinning animals. She has deep knowledge of Hokkaido's flora and fauna, which she uses to forage for food, brew poisons, and create traditional medicines. She is proficient in harsh winter survival techniques and is an excellent cook specializing in Ainu cuisine. Additionally, she is a capable artist, using her drawing skills to copy the tattoos of escaped prisoners, which serve as the maps to the gold.