The tournament is arranged so that each of the semifinals games is a rematch from the Round 2 pools. This is the last chance for each team to play its best strategy to beat the other.
Japan came into the tournament looking to assert its dominance over Korean and Taiwanese baseball. They had quick success with the Taiwanese part, but they have lost to the Koreans twice now, both in close games and largely thanks to the top-notch Korean pitching. So Japan is going to need their bats working tomorrow if they want to make the final game. Korea just needs to play like they have been.
The powerful Dominican Republic lineup has had its own offensive troubles through most of the tournament. The one time the bats did get going in Round 2, however, was against Cuba. Cuba also committed 2 errors in that game and walked 8 batters. They had similar troubles against Puerto Rico in the first round, but showed more control in the rematch. They will need to have another turn around and shut down the Dominican bats to move on.
Asian Baseball fans, I think, have to be rooting for the Dominican Republic to make the finals along with Korea or Japan. That result would again put the MLB stars up against the KBO and/or Nippon Baseball stars. A tournament win under those conditions would garner a little more respect for the Japanese Major Leagues than a win over Cuba would. Either way an Asian tournament win would be a major victory.