Tower Defense is the Ultimate Defense Technique

A single email arrives for the protagonist who has cleared the highest difficulty of Death Parade TD (a VR tower defense game). A privilege granted only to those who have conquered the highest difficulty — the right to test-play a brand-new title. A world indistinguishable from reality. A game by tower defense, for tower defense. The protagonist, overjoyed by how entertaining the content is, dives deep into it with passion.