I reincarnated as a third-rate villain whose only purpose was to become the protagonist's stepping stone. If I fail to fulfill my role, the protagonist will never awaken his true power... and the world will end. So I accepted every betrayal, every wound, and every sacrifice without complaint. All I wanted was to save my favorite heroine and give everyone the happy ending they deserved. Then everything went wrong. An unexpected incident turned me into a beautiful and fragile girl. Before I could figure out why, the protagonist discovered the truth—that every tragedy he had overcome was only possible because I had silently suffered in his place. "...Why didn't you tell me?" From that day onward, the hero's gaze changed. He stopped looking at the heroine. Instead... He only looked at me. "You've sacrificed enough." "I won't let you throw your life away again." "If chaining you to my side is the only way to protect you..." "...Then I'll gladly become the villain."