All Nippon Airways Mileage Club - Booked 2 seats for one person. And could I use both tickets?

I purchaed S class economy ticket for ORD-NRT round trip for November.
I have also booked a business class seat for the same flight by using UA mileage.

Do you think I can use both tickets?
I would like to get the mileage by using economy class.
I know some people have to book 2 seat for large sized, cello or guitar.

The S class is not upgradeable to Business. But, B class is.
I did not purchase B class, as I will not stay in Japan for 5 days which is the minimum stay reqired.

They will probably cancel out your S class seat due to double booking, especially if the plane is filling up.

Thank you ctflyer3000 for the response.

I went to ORD this morning and the ANA agent at the ticket counter
verify that I could get 2nd seat but I can not get the mileage on it,
and I could not purhcase a chair(so they call) in a different cabin.

I was told it is a very big issue that the number of passengers have to match
exactly the one on manifest. If someone purchase 2nd seat to carry a music instrument, the seat is marked occupied but there will be no person's name so that it will not be counted as a passenger.

Anyway I will have to pay $200 penalty and get the refund on S-Class.