In the country of Rimguard, a mysterious event shook the country and its people just 12 years prior. As time passed, memory of the incident began to fade while peace reigned over the land. Sisters Yui and Rena live a quiet life in the Enastria Empire until a large mecha suddenly attacks their peaceful home, changing everything. The girls become caught in a vortex of destiny and godly revival.
12年前，利姆加爾德王國發生的事件在留下了巨大的謎團的情況下，正從人們的記憶中被忘卻。時光流轉，主人公唯和蕾娜兩姐妹在艾納斯特利亞皇國度過著平穩的日常。某天，一台巨大機體襲擊了艾納斯特利亞。以這一天為分界線，少女們的命運被捲入了漩渦當中。