A million yen, under the gold standard, was 48225 troy ounces. To-day, that many ounces of gold would cost US$92,929,575 (¥13,335,626,337).
Of course, the metal value of a modern gold representation of ¥1,000,000 might have a nominal value much greater than the value of the gold that it actually contained.
An iron ¥1,000,000 would have face value greater than the metal value.