user: Question: Tournament of Tokyo, Japan, and a Score of 4–6, 6–4, 6–4 had which date attached?
Columns: ['Date', 'Tournament', 'Surface', 'Opponent in the Final', 'Score']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['April 20, 1997', 'Tokyo, Japan', 'Hard', 'Amy Frazier', '4–6, 6–4, 6–4']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Tournament" = 'Tokyo, Japan' AND "Score" = '4–6, 6–4, 6–4';