Uncertainty fuels their fear of being in danger as weather reports forecast snow and wind for Fukushima where the damaged nuclear plants are located, blowing southwest toward Tokyo and possibly carrying a nuclear cloud there before blowing east out to sea.
"My friends are evacuating to the south. Some of the foreign exchange students are going back to their home countries. My news feed on Facebook is nothing but updates on where they are escaping to. It's making me worried. My boss sent me a message to stay indoors," said Oka.
Others, however, are still dealing with the nightmare of the quake and tsunami.
At a high school gymnasium in the ravaged coastal town of Minamisanriku, some 400 people were sleeping on torn up cardboard boxes on the floor. Volunteers provided what food they could -- a rice ball with some soup and water.
As his wife slept beside him, huddled in blankets, her bandaged face etched with exhaustion, 81-year-old Kaneo Karino described their extraordinary story of survival.
"My wife and I were at home downstairs when the quake struck," he said. "The furniture fell on top of us and then we heard the emergency services ordering us to evacuate. I started to get up but I walk with a cane and it took me a while. And that's when the tsunami hit, whoosh, bursting into the house.
"I was thrown up against a floating log which I grabbed onto. I couldn't see my wife anywhere and then she came to the surface, so I grabbed her hair and pulled her onto the log. A few times I had to swallow some dirty water."
They swam to the top of the stairs and then climbed to their roof.
"We waited 15 hours before being rescued by helicopter," he said.
As he told his story he frequently reached over and gently touched his sleeping wife.
"I am worried about her health because this whole ordeal has been so exhausting. When we finally came to the shelter she fell in the bathroom and hit her head," he said.
He spoke of his fears for his small village of 300 families who have lived there for generations.
"As we flew away I looked down and saw that the entire village was gone. I have no idea if anyone else is alive," he said.
A message board outside the shelter entrance was covered with notices from people looking for family and friends. With almost no means of communication or transport, so many have no clue where their loved ones are or if they are even alive.
One man approached an ABC News crew and asked if they could look out for his daughter and newborn baby granddaughter. He thought they were at another shelter.
Another woman broke down as she said that both of her husband's parents are missing. "We have hope," she said in broken English, but her eyes were filled with fear.
"My daughter couldn't sleep last night because a young boy was crying through the night, 'Where is my daddy? Where is my daddy?'" she said.
ABC News' Bill Weir and Russell Goldman contributed to this report.