CREATE TABLE table_26458 ("Special" CLOB, "Original airdate" CLOB, "Iron Chef" CLOB, "Challenger" CLOB, "Challenger Specialty" CLOB, "Theme Ingredient" CLOB, "Winner" CLOB)

Who was the challenger when winner was kimio nonaga?
SELECT "Challenger" FROM table_26458 WHERE "Winner" = 'Kimio Nonaga'
SELECT "Challenger" FROM "table_26458" WHERE "Winner" = 'Kimio Nonaga'