This is an example of how one plot can ruin the whole series. Tatsuya is a siscon, while the reverse can be said to Miyuki. But when it is revealed that they are truly realted by blood but still engage and I do believe that they'll end up getting married in volume 32. things get sour. What the fuck did the author think ?

The series shows a good scenario when magic has become common sense, while creats intense situations and exciting magic fights. But things are completely falling apart because of an incident.

The art is at least fine.

In conclusion, I can't no longer understand what the author truly wants to convey before and after the existence of that flag. It is interesting in the first place, but quite spoiled then.