Masato vs. Yong Soo Choi
Yong Soo Choi does have more than decent credentials as a boxer. From 1995-98 he held the WBA super featherweight strap. He has also had some success under kickboxing rules, racking up a couple of KO wins, though he is on a lower plane than Masato when it comes to K-1.
The 2003 K-1 World MAX Champion put in the performance of his career in this year's finals against Buakaw Por.Pramuk. Going into the fight, Masato was largely thought to be finished as a tournament fighter, his legs having given up on him a long time ago. But Masato took the fight to the Thai and made it to the finals only for his body to quit on him in the second round.
Prediction: Masato by TKO in the second. Masato's legs are just about done, but he'll have enough in them to chop down Choi. Boxing does not equal K-1, and Masato is an expert of making that evident. This is just an exhibition match for Masato, so expect it to play out like one.