That year, human beings abandoned all sentient beings and headed towards the future carrying the hope of sinful existence.
That year, the silver-gray building cast a long silhouette under the last ray of sunset, with a faint red-purple edge. The sword princess looked like a steel forest, forming a magnificent scene at sunset.
Among the lights of thousands of houses, in the small bright window is everyone's happiness with a heavy past.
That year, dragging her dark and gorgeous tail feathers, she built a mirage of happiness amid the cruel truth.
That year, when the phantom of happiness was shattered, what followed was endless betrayal, torture and exploitation of people's hearts. Where would she go?
In the 22nd century, this dark and flowing world began to revolve, intertwined with war and fire, blood and tears, heartache and separation, weaving together this world.
But this time, I will protect you.
Concise version
The bloody and dirty laboratory, the pleasure of cutting open the skin with a cold scalpel. After escaping from a place of despair, the people she cherished died because of her.
After leaving this city, returning to my hometown, and regaining her memory, the person I love most treats humans and her like this.
What should she do when she discovers that the cause behind everything is herself?
She is the original sinner, and "she" is the original sinner.