Koto Okubo, from Kawasaki, was born on Dec. 24, 1897, and died Saturday. Officials are not releasing the cause of her death.
Kawaksi Municipal Government said she enjoyed spending time with her son, who lives at the same nursing home.
The Kyodo news agency said the oldest person now living in the world is Jiroemon Kimura, a 115-year-old also from Japan.
Kyodo said Okubo acquired the title of the oldest woman alive in December when a 114-year-old woman died in the United States.
The news comes soon after Mamie J. Lewis Rearden, 114, died Jan. 5 after being the oldest person in the United States for 16 days, The Edgefield Advertiser Reported.
Rearden was a retired educator and social worker from Edgefield, S.C.