I wonder if anyone can recall this show. It doesn't seem to be widely remembered as I never see it on any relevant lists.
A 1980s miniseries set in Antarctica after a worldwide pandemic. Survivors consist of Antarctic research base staff, and at least one nuclear submarine crew that turns up later. The various international bases try to unite to survive. They have a problem with men outnumbering women. After some time the sub does a tour of the Pacific to search for survivors, they visit Tokyo and San Francisco but find no signs of life. One of the crew leaves the sub in SF to try to find family.
It was basically a US show, but Japan features somewhat prominently, so was possibly a co-production.