The Yakult Swallows will be taking on the Yokohama Bay Stars in a two game series at Okinawa Cellular Stadium Naha beginning tomorrow. It will be the first NPB Ichi-gun game to be played in Okinawa since the Hiroshima Carp played the Taiyo Whales in a two game series on 5/17 and 5/18/1975.
The the Swallows and Bay Stars arrived in Okinawa earlier today and practiced at the stadium.
It seems that the stadium has a number of possible trouble areas. As mentioned in a Sanspo article:
The foul poles are about 50 cm away from the fences, meaning that batted balls could wrap around the poles making close home run calls down the lines difficult to judge.
An apartment complex beyond the right-center field wall (specifically the lighting) could become a distraction for home plate umps (and possibly batters) when tracking balls out of the pitchers hand in order to call balls and strikes.
The outfield grass is short and the ground is hard, meaning that the ball could move fairly quickly once it hits the outfield.
And according to Kyohei Muranaka, it seems the mound feels a bit "sandy."