[Replying to Kyousuke when he asked her why she wears a school uniform in weekend] Because it's so cute... and, uh, I don't have many clothes. But that's not what you really wanted to talk about, is it? [after hearing out Kousuke about the mysterious email] There's no doubt in my mind. That's 'Maou.' 

'Maou' is japanese, or at least well-versed in the Japanese language. He has also received typical Japanese musical training and education. [smallish pause again] 'Oh, come, lovely child! Oh come thou with me! For many a game I will play there with thee;' the way he translated Goethe's poem here just reeks of a German language textbook in Japan. Furthermore, people outside of Japan know that the Japanese language uses kanji. Play, game... these are all simple enough kanji that even foreigners would know to use them properly. Since he used hiragana despite that, we can probably assume that he was intentionally going for a creepy vibe, and that he enjoys playing around with people in order to get a reaction out of them. And, at the very least, 'Maou' is someone who knows your emai

[Beginning of Chapter 2 to Kyousuke] Yo... Have you heard the good news?! [Kyousuke asks what's with that all of a sudden, smiling] Nothing, I just wanted to say that. [back to normal self] Seriously, what's up? Why are you wearing a suit? [Kyousuke asks why isn't she at school, smiling] I'm not feeling well, so I decided to take the day off. Can't you tell by my gloomy face? [Kyousuke says that she always look gloomy and she should get a haircut] Huh? I'm hurt. I grew my hair out for you, Azai-san. Regarless, I'm very hurt. How much so, you ask? Well, at least enough to require you to buy me dinner tonight.