I noticed today, while playing Grisaia no Kajitsu (English version, since my Japanese is really bad), that when I click on a menu option while using Michiru's voice to voice the menus, she ends her sentence with "じゃないんだからね" (one example being clicking "Extras," which causes Michiru to say "おまけじゃないんだからね"). I'm not entirely certain that she uses the ん sound, but it sounds like it to me. It sounds as if she is telling me that there is no omake, but I feel like I'm missing the importance of the "んだからね". She is supposed to be a tsundere (well, a fake tsundere anyway), so that likely plays into this.
Here is a short clip of her saying it (4 seconds, made with Windows 7's sound recorder), so that you all may tell me that I terribly misheard everything and should give up on Japanese forever.
I converted it to a wav (using online-convert.com), so it should play without being downloaded, I think.