CREATE TABLE table_31384 ("Value" TEXT, "Dimensions" TEXT, "Main Color" TEXT, "Obverse" TEXT, "Reverse" TEXT, "Watermark" TEXT, "Date of issue" TEXT)

What is on the reverse side of the 100 coin?
SELECT "Reverse" FROM table_31384 WHERE "Value" = '₩100'
SELECT "Reverse" FROM "table_31384" WHERE "Value" = '₩100'