A Japanese soldier's "good luck" flag was donated to the Chongqing China Three Gorges Museum on Wednesday to commemorate the 85th anniversary of the breaking out of Baituan Dazhan (The Hundred Regiments Offensive).

The Eighth Route Army had seized the flag during the Chinese People's War of Resistance Against Japanese Aggression (1931-45). It has been proven to be the largest of its kind known to be seized and preserved in China, and is also the only one surviving from the Hundred Regiments Offensive, the museum said.

According to Liu Jingyu, a curator at the museum, the flag bears the words "Eternal Military Luck" and numerous signatures from the soldier's family and friends, embodying their wishes for his safe return from the battlefield.

"While China does have other military flags, this one holds a special place because of the potentially invaluable insights it offers for historical research," said Bai Jiujiang, deputy director of the museum.

The donation was initiated by Su Liya, 76, a local of Chongqing who has been the flag's custodian for years. "The donation today is not just the transfer of artifacts but the entrusting of a heavy historical memory, and a solemn commitment to passing on the spirit of resistance," she said.

The flag's journey began when it was captured by the Shanxi Youth Anti-Enemy Death Squad during the Hundred Regiments Offensive. Su Liya's mother, Su Li, who served as a propaganda officer in the squad, safeguarded the flag for decades.

Born into a landlord family in Shanxi province and driven by a strong sense of patriotism, Su Li left her family and joined the Eighth Route Army at 16. She later participated in several campaigns during the War of Liberation (1946-49). After the war ended, she chose to settle in Chongqing.

At the donation ceremony, Su Liya, accompanied by family members, also donated a dozen other artifacts, including her mother's wartime medals and retirement certificate.

The Hundred Regiments Offensive, launched by the Eighth Route Army in North China, was a large-scale counterattack against Japanese forces. It was the largest and longest campaign during the stalemate stage of the war and remains a symbol of resilience and defiance in the face of aggression.