Live, die, live.

Some people woke up in a place unknown to them.

They were unknown to each other, and everyone was supposed to be dead.

They were perplexed, and unilaterally offered "some extension to their lives" for a mysterious being in exchange for purging ghosts of this world.
Only those like them, once dead, but alive, could find, touch and kill spirits that would otherwise be imperceptible to normal senses.

However, reincarnation was not without side effects.
An absurdly high libido, the restlessness of the next meeting and the fight, and the fear of a near end will come to demand its price, eventually.

Meanwhile, worldly life is about to begin again, but with death itself as the new neighbor ...