The heavy rain and flooding that continued in northeastern parts of the country Friday was an unwelcome reminder to many Tohoku residents of the horror four and a half years previously, when the Pacific Ocean poured inland and left around 20,000 people dead or missing.

"Efforts to reconstruct survivors' lives and mental care are still only halfway complete," said Yuichi Otomo, 46, of Tagajo, Miyagi Prefecture.

Otomo was taking part in reconstruction work Friday in the Yuriage district of Natori city — as the rain fell.

The tsunami claimed the lives of more than 700 residents in the district.

"Many people lost their family and everything else that they loved," Otomo mused. "I sometimes wonder if I have the right to live on." A subsea quake that struck on March 11, 2011, unleashed a wall of water, devastating parts of Japan's northeastern coast.

TV coverage of the deadly floods and mudslides in Ibaraki Prefecture on Thursday was a chilling sight to some survivors of the earlier disaster.

"I never imagined something like this would happen," said Hidetaka Kawabata, 39, who lives in a temporary housing complex in Koriyama, Fukushima Prefecture. "It reminded me of what I saw in the 2011 disaster."

Kawabata, an evacuee from the city of Iwaki in the prefecture, lost a sister in the tsunami whom he had been close to.

"I can't help recalling the tragedy every 11th of every month," Kawabata said. "We shall never forget what happened that day, no matter how many years pass."