That would be considered...
Spoiler for ep.1:
A bad game ending.....
WTF! Almost the whole cast died except for the katana wielding "Category A". So what if Tooru was actually under control of the bad guy and that's why the "Category A" sliced him. She sliced off the control device and he's actually alive whereas the others got killed assuming Tooru is suppose to be the main character. "Category A" is not actually a demon but one of the ones trying to kill the demons and is the other "real" main character. She was only perceived as the demon because of the control devices. Doesn't Category A look like the girl in the manga pic (3rd cover top row)?
Also, that boy with the blue butterflies I believe is also a manga character IIRC (Katz***** Mit*****).
If Category A had sliced Tooru's neck, his head should have dropped off.
Also what if Natsuki = Aoi and the tagline also refers to Category A x Tooru? Of course, that would mean that Tooru may really be dead and the show timeskips to the new (real) cast next week. And maybe the new cast is more inline with the manga characters
Looks like we have to wait 1 week to see how this resolves....
A very good 1st episode. The BGM was extremely nice.