In an interview with the chess Web site chessbase.com conducted Aug. 22, Watai said in Fischer's arrest messed up their life together, reported Mainichi Shimbun Wednesday.
"Marrying him legally may be helpful to avoid the possible deportation and enable him to get a permanent visa in Japan," Watai said.
Fischer, chess world champion in 1972, was arrested at Narita Airport July 13 for traveling with an invalid passport. He is fighting a deportation order in the East Japan Immigration Bureau Detention Center in Ibaraki Prefecture.
Watai said the former chess champion had "calmed down" after an early period of anger.
Susan Sarandon 'very excited' about daughter's pregnancy
Jessica Simpson shares three-way kiss with friends in photo