On June 8 Nguyen Van Duc, 23, had heard cries for help from a woman in a parking lot in Iseda Town, and discovered her husband had passed out in a bathroom.
Duc called an emergency line for help, and the man was taken to hospital but discharged the same day.
Duc was awarded a certificate of merit by the the West Uji City fire department last week for his bravery and timely help despite the language barrier, Kyoto Shimbun newspaper reported.
There are around 433,000 Vietnamese nationals living in Japan, accounting for 15.7 percent of all foreigners, according to the Japan Immigration and Residence Administration.