CREATE TABLE table_31143 ("Season" FLOAT, "Winner" TEXT, "Runner-up" TEXT, "Third place" TEXT, "Fourth place" TEXT)

Who was the runner up the season that Sagawa Express came in fourth?
SELECT "Runner-up" FROM table_31143 WHERE "Fourth place" = 'Sagawa Express'
SELECT "Runner-up" FROM "table_31143" WHERE "Fourth place" = 'Sagawa Express'