Sergeant Itō serves as a non-commissioned officer in Captain Inouye's Imperial Japanese Army unit during the Burma Campaign in July 1945. He participates in the platoon's group choral singing, activities organized to bolster morale amid wartime hardships and the unit's retreat toward Thailand. Following Japan's surrender, Itō enters British captivity with his comrades at the Mudon prisoner-of-war camp. He shares the unit's profound concern over Private Mizushima's disappearance after a failed mission to persuade resistant soldiers. Itō engages in practical efforts to locate Mizushima, coordinating with a local Burmese woman transporting goods in and out of the camp.

When the platoon observes a Burmese monk resembling Mizushima, Itō joins his fellow soldiers in attempting communication, though the monk avoids interaction. This prompts the unit to devise a plan involving a parrot trained to say "Mizushima, let's go back to Japan together," a collective effort Itō supports to reach their comrade. He witnesses the emotional climax as Mizushima, revealed as the monk, communicates his decision to remain in Burma through the returned parrot and a letter. Itō shares in the unit's tearful response to Mizushima's commitment to burying war dead and pursuing Buddhist teachings, accepting this resolution without further intervention.

Throughout the narrative, Itō functions as a loyal and emotionally engaged member of the unit, reflecting group dynamics. His military role includes logistical responsibilities like managing supplies and facilitating communication with local Burmese contacts during the unit's movements and imprisonment.