Hitsugaya's post made me wonder, what if everyone in that prefecture is starting to gain some spirit awareness?
It really wouldn't be too off since the whole current Manga story arc is focused around the fact that
Aizen Is interested in Ichigo's home town to use for making the Key to the "King's" palace. And the whole reason for this as quoted from chap 233 is that Karakura Prefecture IS an area with high spiritual density.
So mabye the whole thing with Keigo and Tatsuki is that the presence of Ichigo's massive reiatsu mearly sped up the awakening of their spiritual awareness and that mabye its something about Karakura itself that allows people to have spiritual awareness. Once again, just a thought.
And in advance yes i know, "High Spiritual density" can be taken as having alot of people like Ichigo and Crew around. But, that dosn't necessarly rule out the aforementioned thought.