Alice Hodgkinson, who had been working as an English teacher, had been missing since July 1 from her home in Kanagawa after failing to turn up for work in Tokyo.
Her family said on Friday they had received the “worst news imaginable” from police in the country.
She had lived in Japan since last year and was working for the Shane group of English schools.
Her father Steve, 68, told The Sun: “We were notified last night. Police told me that they had found Alice’s body. It was the worst news imaginable.
“We are devastated and it is a very difficult time for our family.”
He added: “We are at a complete loss and her mother is struggling, she’s beside herself with grief.”
The family want to repatriate her body as soon as possible.