"If there were a land of blind-folded people, would they understand the concept of sight? Sometimes, my 'blindfold' slips a little bit." - Kanade
What if the world is like a place filled with blindfolded people, and then every once in a while your blindfold slips, and you can see a glimpse of another time... well, that's exactly what Kanade is experiencing. When she bumps into a person, every so often, she gets to see a bit of that person's future. Thus the title "Land of the Blindfolded", except for her and two other that are in kahoots.
One day she bumps into Arou, and luckily, she didn't "see". On the other hand Arou "saw", and from then on knew her secret. Thing is, Arou also had an awesome ability that makes him see through time, but back into the past. He and Kanade are looking into two opposite directions of the timeline and balance each other out. Although while Kanade's blindfold slips a little, Arou's blindfold is gone, and he can see through the past indefinitely. Don't they just make the perfect couple?
Not if Namiki had anything to do with it. Namiki had the same power as Kanade, although his is more pronounced as he uses it constanly in gambling to pay his own rent as his parents disowned him because of his abilities.
So they make quite the trio who fights for justice. Truth of the matter is, only Kanade wants to meddle with other people's affairs to make sure nothing bad happens to them as she sees her power as a venue to help people. Both Arou and Namiki thinks otherwise though and are only helping people to make sure Kanade doesn't get hurt in the process (cause they both like her, but you already knew that didn't you?) You see, if you save someone from falling into a hole, they'd even get mad at you for getting in the way. They aren't even the least bit thankful that you saved their life...but Kanade doesn't mind, that's a better option than to see that person getting hurt when she could have done something about it.
So if you see their power as a blessing or a curse is all up to you, but through that they get all sorts of rich experiences and encounters for themselves, even through other people's lives. One thing was sure, they wouldn't even have met if it weren't for their extraordinary gifts. (This kind of reminds me of the Time Traveler's Wife, where the middle-aged guy wouldn't even have met the little girl if it weren't his ability to hop through time uncontrollably.)