Hulunbuir is the vast steppe border region where Lieutenant Mamiya’s wartime experience becomes the defining break in his life. It is presented both as a strategically uncertain frontier that the Kwantung Army struggled to map and as a landscape of such scale that Mamiya felt his sense of self dissolve within it. The region’s geography, military importance, and remembered darkness of a well connect the war narrative to the novel’s reflections on memory, survival, and the limits of explanation.

Borderland and Strategic Setting

The maps available for the Hulunbuir border region with Outer Mongolia were crude, scarcely better than maps inherited from the Manchu dynasty. The Kwantung Army had undertaken surveys after the establishment of Manchukuo, but the area was enormous, and the western Manchurian landscape offered few landmarks against which to check a map. Mamiya’s assignment involved examining the western border’s topography and improving the available maps, a task made difficult by the steppe’s openness and the uncertain location of the frontier.

The lack of precise maps reflected a political predicament as well as a geographic one. Manchukuo shared borders with the Soviet Union and Outer Mongolia, both sensitive to incursions; unilaterally fixing the frontier on an official map could provoke an international crisis. The army, already committed to the war in China and lacking the forces for a major confrontation with the Soviets, preferred to leave the northern and northwestern borders indefinite. Yet military planning required detailed combat maps, including information about possible encampments, artillery positions, marching times, water supplies, and fodder. The same ambiguous frontier that officials sought to defer therefore remained a practical vulnerability in the event of war.

Mamiya’s Mission and the Open Steppe

Mamiya was selected to command a small escort accompanying Yamamoto because of his topographical responsibilities, not because of combat experience. He was to contribute his knowledge of the district and gather additional information for the maps. The party was deliberately small: a larger group risked attracting Outer Mongolian troops along the border. Hamano was the escort’s experienced fighter; Corporal Honda, newly arrived from home and seemingly untested, had been specially assigned for reasons Mamiya did not yet understand.

After five days of preparation, the party traveled by train from Hsin-ching to Hailar, then by truck past the Khandur-byo Lamaist temple to a Manchukuo Army observation post near the Khalkha River. Mamiya estimated the drive at roughly two hundred miles. The surrounding land offered no reliable markers: he saw grass-covered mounds, an unbroken horizon, and clouds, and could only guess their position from how long they had been traveling. In that emptiness, he experienced the landscape as ocean-like in scale. The account links this physical vastness to a weakening sense of personal boundaries, as if the mind expanded into the surrounding space and loosened its attachment to the body.

The Well and Mamiya’s Recollection

In the account Mamiya later gives to Toru Okada, Outer Mongolian troops throw him into a deep, dark well in the steppe after his leg and shoulder have been broken. With no food or water, he believes he is waiting to die. He relates this ordeal to an earlier experience of witnessing a man’s death and to an intense shaft of sunlight that reached the bottom of the well for a few seconds on two consecutive days. In his tentative explanation, the extremity of his physical condition concentrated his consciousness, and the light seemed to disclose a living but indistinct presence at its core. He could not make out its form before it vanished.

Mamiya does not present this interpretation as certain knowledge. More than forty years later, he says he cannot explain what the light meant, and identifies his account as a hypothesis rather than a logical conclusion. What remains certain to him is the experience’s consequence: after it, he was no longer the person he had been. His narrative returns repeatedly to the steppe and the well because those memories remain more immediate than the decades that followed.

Memory, Survival, and Significance

Mamiya describes the later course of his life as an empty interval: he lost a hand in battle against a Soviet tank unit, endured a Siberian labor camp, returned to Japan, taught social studies at a rural high school for thirty uneventful years, and eventually lived alone, working the land. Yet these years seem less real to him than the wartime experience in Hulunbuir. The remembered landscape becomes the point across which his memory leaps, while the well’s brief light marks the change he can neither forget nor fully interpret.

Hulunbuir thus joins military history to a personal account of trauma without resolving either into a single explanation. Its immense terrain exposes the limits of maps and military certainty; its well becomes the site of an experience Mamiya can report in detail but cannot conclusively explain. The region’s narrative importance lies in this double role: it is a real and strategically contested borderland, and the setting of the memory that makes the remainder of Mamiya’s life feel, to him, like an afterimage.