user: Question: What grand prixs did Daijiro Hiura win? 
Columns: ['Round', 'Date', 'Grand Prix', 'Circuit', 'Pole Position', 'Fastest Lap', 'Race Winner']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'March 29', 'Spanish Grand Prix', 'Jerez', 'Luis Salom', 'Daijiro Hiura', 'Luis Salom']
SQL:

assistant: SELECT "Grand Prix" FROM "Table" WHERE "Race Winner" = 'Daijiro Hiura';