Wow, that was a very interesting and unique game. As a student studying Psychology also, I found the mental illness aspect of it was particularly fascinating. I think I've spent too much time on this now, having found all five endings and the easter egg. Haha XD
There's a couple of points I wanted to pick up on. One is on Kimiko who I felt to be, I suppose, a realistic but nevertheless dislikable character. Is it possible that she had psychopathic traits also? It's just I couldn't help but notice how selfish she was and at certain points, how callous she reacted towards her own daughter. In particular, I'm referring to the "I win" bit.
Also, despite being half Japanese myself, I found it quite a culture shock. (I'm neither saying this is positive nor negative way). I just tend to sometimes forget other cultures' views differ on incest, passion killings and homosexuality. On that point actually, Naoki did tend to perpetuate the whole gay stereotype. But then, he was a great character, so I can perhaps forgive you for that. ;)
But all in all, a brilliant and hooking game! It is quite relieving now though, having escaped the craziness and intensity of the 'Nowhere Safe' world to come back down to normal reality (well, 'normal' for me anyway). Thanks for providing us with such a great game!