user: Question: What circuit was the race where Hideki Mutoh had the fastest lap?
Columns: ['Round', 'Circuit', 'Date', 'Pole Position', 'Fastest Lap', 'Winning Driver', 'Winning Team']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Fuji Speedway', '2 April', 'Benoît Tréluyer', 'Masataka Yanagida', 'Benoît Tréluyer', 'mobilecast IMPUL']
SQL:

assistant: SELECT "Circuit" FROM "Table" WHERE "Fastest Lap" = 'Hideki Mutoh';