Some 400,000 households in the Kanto region are still without power, days after typhoon Faxai hit the area.
The Tokyo Electric Power Company says it will take at least until Friday to fully restore electricity in Chiba prefecture.
Workers are busy replacing toppled power poles.
A woman in her 80s was taken to hospital with breathing difficulties.
People are also having trouble getting a phone signal. The mayor of Kimitsu City described the situation.
Mayor Hiroko Ishii said, "The damage is tantamount to an earthquake. It's a really critical situation for us."
Continuing hot weather is exacerbating things as people can't use air conditioners and have no running water.
Two have died from heatstroke in Chiba.
Kazuyuki Shiokawa of TEPCO Power Grid said, "We expect to restore power on Thursday in Chiba City and the surrounding areas. But we will need at least two more days for other areas including Narita City and Kisarazu City."
People have been lining up to get drinking water.