Me for Myself? a Bit Interesting

(Yandere + single female protagonist + no system) He stood frozen in front of the floor-to-ceiling window, with the city lights outside the window, and behind him his ex-girlfriend who was paranoid about high school. The flawless disguise he thought he had was shattered by the soft sound of the door lock. A pair of warm arms wrapped around him softly from behind. She pressed against him, and her breath blew warmly against his ears: "Finally... Until you come home." She held his hand and led him to look at the carefully reproduced cage. Her voice was soft and charming: "Look, it's exactly the same as our design back then. In the past three years, I have been thinking about how to keep you here... Every day." Her fingertips touched his lips, slid to his Adam's apple, and finally grasped the fingers he tapped subconsciously. "Your voice, your little moves... You can't fool me." She chuckled, "Your disguise is really ridiculous." She raised her face, tears welling up in her eyes, but her smile was as charming as poison: "Now that you have walked in, don't even think about leaving again." "If you ask me if I'm playing a stand-in game?" She smiled, but her tears fell, "No, what I have been waiting for has always been you. Now, the time for trial has come. Pay the price for leaving without saying goodbye - with the rest of your life."