Q&A is up. (trans from 4chan)
http://togetter.com/li/684871

http://worldcosplay.net/photo/2114338
Nio cosplay here
Q: Otoya pulled a funny face after seeing Nio's body. Did she know about Kuzunohas' tattoos or was she just disturbed by what she saw?
A: I guess she was afraid of the sorcery, or some similar sensation.

Q: Haru graduated but, did she spend 3 years studying after her last fight with Tokaku? Everyone from Black Class got their graduation certificates, does it mean they actually graduated exactly like Haru?
A: The Black Class is a special curriculum, it doesn't span over 3 years. Also, the graduation certificates were prepared for Mizorogi's sake.

Q: What did Chitaru mean by "I am incapable of saying this..."?
A: Somebody with a strong sense of duty like Chitaru couldn't easily admit that she changed her feelings towards her former rival Hitsugi.

Q: Kaiba seems to be quite a wise man, but why did he send Tokaku to the Black Class? I imagine he did it as her homeroom teacher, for the sake of her education and growth.
A: Kaiba might be a pretty unpleasant person, but he's a wonderful teacher. He's the ideal teacher, according to Kouga Yun.

Q: What was Tokaku's reward in the end?
A: She didn't say what she wanted. I guess it was probably something like "I want to be with Haru". It looked like she was only doing her mission from the start.

Q: Nio didn't hand out her advance notice. Did she leave the Black Class?
A: Nio is different from other students, she's the arbitrator and because she's the Admin's favourite, she doesn't need an advance notice.

(Nice, Nio x Yuri is canon)

Q: How did Tokaku manage to get into the cemetery where only members of the clan can enter? Even if the security was weak, how did she even find that place?
A: I guess she followed Haru. Also, winners of the Black Class are allowed to enter the cemetery.

Q: Why did the Admin give Tokaku a new advance notice? I can only see it as her pressing Tokaku to kill Haru, but if Haru actually managed to survive this, that certainly would be thanks to her Primer?
A: We haven't developed the setting that far, but I guess that was more or less the Admin's intentions.

Q: Where will Haru live after graduating? Will she live with Tokaku?
A: "That would be nice..." is the idea we had when making episode 12.

Q:Was it Nio disguised as Tokaku who handed out the advance notice to Haru?
A: No, it was the real Tokaku!

Q: Since last week, Haru's phone strap was shown several times and I recalled Otoya saying "Haru's strap has a great value" to Mahiru in the 3rd episode. What kind of value exactly?
A: Mahiru and Otoya saw the strap as a pure memento.

Q: Looks like Haruki will be taking a high school graduation exam. I wonder if she's planning on going to a technical school or a junior college? If so, what subject does she want to study?
A: She hasn't thought about the study subject yet. She hasn't been able to attend school until now, so I guess she realised how fun it is to study at a high school.

Q: Why does Mahiru look so refreshing after the graduation? She then said that she was going to be fine by herself, does it mean that Shinya disappeared?
A: It's a way to show that she moved on with her past. Shinya will keep living in Mahiru's heart.

Q: Chitaru is completely ignoring Hitsugi at first, I wonder if there are some after-effects from her being poisoned?
A: I think she hadn't put in order her feelings so she didn't answer Hitsugi.

Q: I wonder if Mizorogi will get transferred from the Myoujou Academy.
A: Maybe. Or maybe he will be put in charge of a normal class!

Q: There's a mistake in Haru's diary for episode 12. Haruki's name is missing.
A: Sorry, we'll fix that.

Q: It's your last time. Could you tell us a few words?
A: Thanks for watching the series. Don't forget to watch the episode 13 from BD volume 7.