At the beginning of the 20th century, after the Russo-Japanese War, Saichi Sugimoto, a former soldier known as “Immortal Sugimoto,” travels to Hokkaido in search of a vast treasure of gold once stolen from the Ainu people. His only clue is a series of tattoos carried by escaped prisoners, whose combined patterns are said to reveal the treasure’s location. He joins forces with Asirpa, a young Ainu girl who knows the island’s wilderness intimately and whose past is directly connected to the gold. Their search soon attracts soldiers, criminals, and hunters with competing ambitions. Between survival, pursuit, and violent clashes, their journey also explores Ainu culture and the scars left by Japan’s recent history.