HEFEI－While browsing a secondhand book store online in October, Xu, 27, came across a photo and a certificate of Chinese People's Volunteers martyrs killed in the War to Resist US Aggression and Aid Korea (1950-53).
According to the certificate, the martyr named Tian Chunshan came from a village in Central China's Hunan province. Born in 1924, Tian joined the army in November 1949 and died in 1951.
There are two people in the photo, and one of them could be Tian, said Xu, who spent 1,500 yuan ($222) buying the certificate and the photo.
"The moment I saw the record and the attached photo, I decided to return it to his family," said Xu, from Funan county of East China's Anhui province.
Early in the morning on June 14, Xu embarked on a journey to the city of Huaihua in Hunan to look for the martyr's family, taking him more than 1,000 kilometers from his home.
It took Xu more than 10 hours to reach Huaihua by train. He rented a car to continue his trip in the mountainous area until he arrived at the place suggested in the certificate.
"Do you happen to know Tian Chunshan?" Xu asked an old man he bumped into near a local reservoir, showing him the photo at the same time.
Surprisingly, the elderly man in his 80s responded with a positive answer, referring to the man on the left in the photo.
"I only saw him once when I was young. Four people from my village went to the war," said the old man, surnamed Zhou.
Tian never got married, and his mother and his brother died a long time ago. Only his nephew still lives in the village, Xu discovered.
Xu then managed to return the martyr certificate and the photo to the nephew after confirming the information with the local bureau of veteran affairs.
To thank Xu for what he did, the nephew offered him some money, but Xu rejected it. Instead, Xu asked to take a photo with the family before he left.
"It was such a relief when I handed the things to the martyr's family," Xu recalled.
"My grandfather's elder brother died in the war at the age of 27. I heard about his stories many times when I was little, but never saw a photo of him."
His recording of the journey has racked up over 220 million views so far on microblogging site Weibo.
On China's short-video platform Douyin, Xu has received more than 549,000 likes so far.
"Helping a martyr return home is a journey that should be remembered forever," commented a netizen on the video.
The journey has struck a chord with many readers. "Many people have praised what I did, but my act is nothing compared with what the martyrs did. They are true heroes," said Xu.