It's a good series, although it starts off really slow. And it has great villains, with angsty backgrounds and reasons for what they're doing.

But it is meant to be a shounen series, so you'd probably be annoyed with a lot of it. And Mahiro disappears for a lot of the series, and Yuya can be terribly girly. But a lot of people who usually prefer tough women-warrior types find themselves liking her ... she "grows" on people.