There is a kingdom called Kazeria, which has been governing the world more than a thousand years, and people live a peaceful life under their rule. One day, Aurelia, a princess of Kazeria, is sent to Diastan to marry. However, Aurelia and her bodyguards go missing along the way to Diastan.... A search troop is sent soon, but they go missing as well. Kazeria, Amatsu, and Elf, Kazeria's alliance, decide to send elite troops. Like this, Aisis from Kazeria, Nanai from Amatsu, and Kurie from Elf set out for Diastan. What they see at Diastan is a completely ruined Diastan Castle. When they roam around the castle, various monsters attack them one after another and heroines are captured one by one. Aisis finally reaches the master's room and sees....