An elderly female wolf, known as "Mother," roams the harsh Manchurian wilderness during World War II. Her existence as a solitary predator centers on survival, often targeting vulnerable prey like weakened humans in retreat. This established behavior shifts dramatically when she discovers Kiku, a young girl abandoned during the chaotic Japanese evacuation due to severe measles.

Drawn initially by predatory instinct to the incapacitated child, the wolf instead recognizes Kiku's feverish vulnerability. Her inherent maternal instincts override her predatory nature. She actively seeks medicinal herbs known to alleviate the illness and administers them to the girl, directly aiding Kiku's recovery.

Following this act, the wolf assumes a protective and nurturing role as Kiku's surrogate mother, remaining by her side to provide care and guidance. Her development focuses on the internal conflict between her wolf nature and the profound maternal bond formed with the human child. This conflict culminates in a selfless decision: recognizing the fundamental differences between human and wolf needs, she prioritizes Kiku's long-term well-being over her own desire to keep the child. She guides Kiku towards a human settlement, ensuring the girl's safety and integration into human society despite the personal cost of separation.