It's common for someone to pass away and have their soul taken to the afterlife. Once there, a goddess can offer to transfer the soul to a different world she has created. The new world is equipped with exceptional abilities, but the goddess sets a condition - the powers must be used to fight an imminent threat that could devastate the universe.
However, when humans are summoned to this new dimension and given the abilities of a demigod, they often misuse their newfound strength for selfish gain and cruelty.
In this situation, Zyzz finds himself enslaved to one of these otherworldly beings who promises to help him find his sibling. Fate intervenes when he meets Kaina, the "final summon" chosen by the goddess to eliminate those who didn't fulfill their duties...
