user: Question: Who was the Japan Open runner up?
Columns: ['Date', 'Tournament', 'Winning score', 'Margin of victory', 'Runner-up']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['30 May 2010', 'Diamond Cup Golf', '–16 (65-68-68-71=272)', '2 strokes', 'Koumei Oda']
SQL:

assistant: SELECT "Runner-up" FROM "Table" WHERE "Tournament" = 'Japan Open';