This is a Yajilin puzzle.
(Click for larger size)
I feel obliged to point out something I found in my referral list recently: http://pronter.tumblr.com/. It looks to be a digest of posts from several puzzle sites, a lot of which I (and probably many of you) already knew about. But new to me were some posts from Japanese puzzle blogs which seem to mostly post Heyawake puzzles, and they are both quite hard and extremely nice. Worth a look if that piques your interest.