In a world where humanity can only survive in the area protected by God's Barrier. People who called themselves Adventurers are protecting the people from the threats of monsters. They were able do so with the power called Blessing and a 10 meter tall humanoid weapon called Artificial God.

Two people, Shin and Yuri has wandered into this cruel world by unknown cause. Shin who had obtained the Blessing to create an object started his life as an Adventurer with gun in his hand. Then one day, the village he was residing in are being attacked by the greatest threats of mankind, and then a desperate battle to prevent calamity has taken place. At such time, Yuri that was left behind have awakened the power to summon the Armor of God, Seikishin.

After the incident, Shin was hailed as the Hero and Yuri was called as the True Miko. For the sake of their love, the story of two people who will fight even against God to find a way to return to their home begin.