Koichi Ohtsu is 63, and he realizes now that the last part of his life will be the hardest.

He is prepared for it. If he loses his university teaching job because too few students enroll next semester, he will stay in this tsunami-stricken coastal city and tutor. If the local stores stay near-empty, he’ll drive an hour inland for groceries, then come back to cook dinner. Ishinomaki is home. Weeks from now, perhaps, he’ll be able to walk to the hilltop Buddhist shrine near his house and look down at the city without sobbing.

“I am ready,” Ohtsu said. “I am ready to share the burden.”

Like tens of thousands in the northeastern towns and cities devastated by Japan’s March 11 earthquake and tsunami, Ohtsu is recalibrating his life, trying to reconcile the work that must be done and the time needed to do it. Japan’s far-flung populations were aging and shrinking well before this catastrophe, and in Ishinomaki, one in every three people is 60 or older. Here, as in many places, the ability to rebuild will depend on aging lifelong residents who must choose whether to stay and adapt to discomfort or pursue easier existences elsewhere.

Ohtsu sometimes shakes his head, thinking about how close escape is. Just 30 minutes west, there is no mud, no debris, no suffering. He’s one $4 toll road away from mountains where he loves to ski. Even now, when he drives to these places, he listens to the Beatles and sings out loud. Then he turns back toward Ishinomaki, on an industrial road where the tsunami dumped a world of trash. Minivans are kebabed on telephone polls. Dented freight cars sit on sidewalks. Trees are crusted in mud and newspapers.

“Sometimes it’s very difficult, and even painful, to switch my frame of mind — from this peace to focusing on this,” Ohtsu said, and he turned off the music.

He looked to his left, where a flattened school bus painted with Pokemon characters jutted from the remains of a kindergarten.

“My God,” Ohtsu said.

One of the lucky ones

In a sense, Ohtsu is one of the luckiest people in an unlucky place. He lives atop a hill in a city where everything below the hill became rubble, with 28,000 homes destroyed and more than 5,000 people killed or missing. When a Washington Post reporter visited Ishinomaki last week, Ohtsu served as an unpaid interpreter and local guide. During several days together, Ohtsu explained that he had lost his routine but not his possessions — and he said he feels guilty he lost only this much.

Before the disaster, he would map out his days on a white board in his study. One hour for tai chi. Four hours for studying French, ahead of his March 29 trip to Paris. A few hours for writing his latest book on Japanese linguistics. Bed at 11 p.m. Awake again at 4:30.

Then, at 2:46 p.m. on March 11, a 9.0-magnitude earthquake struck offshore. Ohtsu dived under his kitchen table, clutching his 89-year-old mother. When he emerged, the old priorities were no longer priorities.

He and his mother went the first week without electricity. He checked on his neighbors, found those with damaged homes, and soon 10 people — including three teenage girls — were sleeping on tatami mats in Ohtsu’s small house. He no longer worked on his book. He canceled his trip to France. He stopped exercising. He volunteered at a downtown shelter, passing out food.

He met with a group of fellow professors, and they talked about their school, Ishinomaki Senshu University. Would the students come back? How would they commute, with train and bus lines down? And how would the school cope with the several hundred evacuees living on its campus?

Ohtsu had become a teacher, he said, in part because he liked to think, and teaching gave him time to think. “Who am I?” he liked to ask himself, and after the earthquake, he had clearer answers. He’d lost his wife 13 years ago to a heart attack. They hadn’t had children. Ohtsu was now, foremost, a son — a caretaker for his mother, Toyoko. She needed him. She had early-stage Alzheimer’s, which meant that every day, she woke up and learned all over again about what had happened to their city.

One night, when they were watching TV, the local news showed footage of the elementary school where Toyoko once taught. Now it was a blackened skeleton.

“Look, Mom,” Ohtsu said. “That is your school.”

She covered her mouth.

“Oh, it’s a horrible disaster,” she said.

“The images now on TV — the images just pass away,” Ohtsu later explained. “It’s like she is a Zen priest. She lives in the here and now, in my assessment. Sometimes I admire her more than ever. I don’t treat her like a fool. I tell her again and again, ‘This is what we are now.’ ”

Waiting for optimism

In quiet moments, Ohtsu wrestled with that question: What are we now? Three weeks after the tsunami, he met up with a friend of a friend — an expert in disaster reconstruction — who talked in sweeping terms of hope and rebirth. “We will rebuild,” the expert said.

But Ohtsu disagreed. Sure, maybe Ishinomaki will grow back, he said. But there will be moments of ugliness, and pessimism, and many times when nobody feels reborn. You can’t wrap all the work to come in a platitude.

“Optimism,” Ohtsu said. “I don’t see it yet.”

Ohtsu keeps a blog, where he used to post photographs of the beaches where he walked, the midsummer festivals he attended. In recent weeks he has taken hundreds of photos of the destruction, but these he has kept private. Post-tsunami Ishinomaki still feels too bloody, too exposed, to put on display, he said.

He made a single exception. One day, while volunteering at the shelter, he saw a woman and her grandson crouched behind a truck sharing a bowl of noodles. The grandmother was balding and the boy was wearing a sweat shirt, hood tightened around his face. It was snowing. Ohtsu took a picture, which he later posted. It felt like “a terrible thing to do,” he said, yet he wanted people to see that image because it explained just a little bit about what it meant to him to stay in Ishinomaki after the tsunami.

“Compassion is the fundamental teaching,” Ohtsu said. “Listen to others, feel together. You cannot necessarily help him or her, but cry when other people cry, laugh when other people laugh. Just show your warm face. These are Zen teachings. Everything that is happening here reaffirms my faith.”

Special correspondent Akiko Yamamoto in Tokyo contributed to this report.