It was late March when filmmaker Kazuhiro Soda realized he needed a Plan B. His latest documentary, “Zero,” had won an Ecumenical Prize at this year’s Berlin International Film Festival and was due to open in Japanese cinemas in just over a month. But, in the age of coronavirus, it only takes days for the best-laid plans to unravel.

Soda and his wife, producer Kiyoko Kashiwagi, had arrived in Tokyo from their home in New York for a promotional tour on March 25. A day later, Japan started restricting entry to all travelers from the United States.

While New York was on full lockdown, Tokyo had managed to preserve a fragile semblance of normality — but the strain was beginning to show. Even before the government declared a state of emergency in April, which included a request for movie theaters to close, box-office takings had nosedived.