Tokyo - Japan's four-time Olympic swimming champion Kosuke Kitajima has announced his engagement to a 27-year-old pop singer.
Kitajima, 30, said in a statement he had been going out with Chisa for two years and "was able to devote myself to my competitive career because of her support".
Chisa is the vocalist with the Girl Next Door trio. Her family name has not been publicly disclosed.
In a separate statement on the band's website on Tuesday, Chisa called for her fans' continuing support and said she would continue her singing career.
Kitajima won gold in the 100m and 200m breaststroke at the 2004 Athens and 2008 Beijing Olympics.
He reportedly proposed to his bride-to-be before the London Olympics last summer.
Chisa visited London during the Olympics, where Kitajima failed to defend his titles. He finished fifth in the 100m and fourth in the 200m, but managed to win the silver medal in the 400m medley relay.