Five girls and five boys were simply living their normal lives, when in the first moment they were alone, they were sucked into a vortex and poof!, disappeared. They were taken to somewhere unknown, but they call it the "Through", because it's the universe "through the vortex". They've forgotten almost everything from their pasts, and have quick flashbacks of people who had really strong feelings for them.

What happens now is that each one has a problem.

While one can't feel anything caused by other humans, another cannot make any sounds at all. A mysterious girl tells them that they have to neutralize the each other's "different characteristics" so that they can go back to the real world.
Since there's nothing really to do, they all agreed.