This week’s episode introduces the sister, Kisaragi Momo. This is the part where the supernatural starts to make its appearance, as Momo has the power to attract the attention of those around her. I assume this power is similar to being able to see the future in that it makes your accomplishments seem more trivial.
I didn’t get too far in the manga for this show, so I think I only know what happens up to the next episode. Next week is the recruitment episode where Momo finds more people like her. That being said, not much is known at that point what the direction of the show is and what exactly the meaning of these powers is.