My younger sister, Kurea Kurosaki, is a perfect superhuman. She was born into a wealthy family, possessed exceptional beauty and talent, and was a genuine, gifted young lady who worked hard without being conceited about these qualities. No one can help but respect her. She has no doubt that she has a bright future ahead of her. The way she embodies “perfection” in her body makes everyone who sees her admire her. However, no one knows that behind the scenes, she has been working hard to achieve perfection. What kind of effort is required to maintain “perfection”? I couldn’t even imagine it. I couldn’t even realize it. Because of that, my sister was broken. The one to whom the threadbare Kurea clung was me. What my lovely sister wanted me to do was to spoil her. And then Kurea and I went astray. The line we easily crossed was the world of happiness, blasphemy, and immoral pleasure.