Rukiya's definitely one to look out for. He's still very raw (10-3), but big frame and heavy hands for that weight class. Still 21.
He's fighting Wang Zhiwei on WLF in April 1st. Good prospect matchup. If he wins, he'll probably get a Krush title fight. Rukiya's been calling out Sasaki since the last K-1 event, claiming that he's disgraced the belt and that he will "decapitate" Sasaki.
Fun fact, he's actually a minor celebrity in Japan. He's one of the "Anpo brothers" who were prolific in kyokushin karate when they were kids and got some minor TV coverage.