y85 100 Yen (1975) Okinawa Expo. This is actually a coin that was used in circulation. 120,000,000 were minted. They were minted to mark the Expo in 1975 a commemorative usually is minted after the fact in honoring some one, thing or action.
Yes, I know the second picture is upside down. Didn't figure it mattered too much. And thanks for adding those details! I'm definitely not a coin specialist, myself.