That entire scene with the hand and the ringtone is peak psychological horror. The slow build-up was so well done. Especially combined with the positive delusion that was supposed to fill you and Takumi with some hope. It was also a nice moment for Takumi's character, as it showed that he does care about his sister.
By the way, the "committee of 300" plays a major role in Steins;Gate too. That's actually the organization Okabe was constantly talking about.