Rikako Ikee has been discharged from hospital after completing treatment for leukaemia.
The 19-year-old, who shot to fame with six swimming golds at last year's Asian Games in Jakarta, made the announcement in her first Instagram post for almost four months.
It consisted a hand-written statement revealing she had left hospital after treatment, and how she felt during the chemotherapy.
"After almost 10 months, I finally managed to check out of the hospital. There were some long, trying days but thanks to all the support and kind words, I found the strength to get back on my feet again.
"I felt nauseous and very exhausted during the chemotherapy but I told myself over and over again, ‘It’s going to be OK, this will come to an end.'"
Ikee eyes return to the pool
After her exploits in Indonesia saw her become the first female winner of the Asian Games MVP award, Ikee became a poster girl for the Tokyo 2020 Olympic Games to be staged in her home city.
But she was diagnosed with leukaemia in February after falling ill during a training camp in Australia and began treatment that month.
At July's FINA World Championships in Gwangju, the medallists in the women's 100m butterfly - her best event - wrote messages of encouragement on their hands with Ikee thanking them for their tribute on Instagram.
While Ikee will not be fit for her home Games, she is hoping to make a full recovery in time for the 2024 Games in Paris.
She said, "I know many people think I lost a lot after suddenly having to step away from the pool with the Olympics in sight. But I like to think I was able to learn and think about a lot of things because I became sick.
"As for my competitive career, I will consult my doctor and once I’m cleared, will begin training in the water again. Until then I will train on the ground to build back my strength.
"I’ll keep working towards the goal of winning a medal at the Paris Olympics in 2024."