It's got a sense of humour about itself - even though it has angst as well- which is very appealling.

True. I like the self-mocking stuff. But then of course neither Domyouji nor Tsukushi are typical star-crossed angsty protagonists (a la TJ). They are both bull-headed and immature and the show both mocks them and loves them and I like that too. It's not all "ohhhh, Romeo and Juliet redux," but more realizing the silliness or flaws.