Where to sell pokemon cards as a foreign Tourist on Okinawa

Hi, we are currently staying on Okinawa for a month.
My kid opened a couple of Pokemon boosters and got some really nice hits. He wants to sell a few to buy more boosters. We were in Tokyo before but we couldn't find a place where we can sell them, as we don't have a residency card.
Does anyone know places on Okinawa where we can sell single cards for a decent price as foreigners?

Many thanks in advance 🙂