An 80-year-old woman and her 16-year-old grandson were rescued from their damaged home on Sunday in the city of Ishinomaki, nine days after the northeast was devastated by a massive earthquake and tsunami, NHK public TV said.
NHK quoted police in Miyagi prefecture as saying the two were weak but conscious.
An NHK reporter, quoting a doctor at the hospital to which the two were taken by helicopter, said the two had been trapped in their kitchen after the massive earthquake and survived by eating yoghurt and other food in the refrigerator.
The grandson eventually made it to the roof and waved down a rescue helicopter, the NHK reporter said.
The youth, Jin Abe, had low body temperature, was shaking and had no feeling in his left ankle, the reporter said.
An official at Ishinomaki's Red Cross hospital said the two had been carried into the hospital and were getting treatment.