Ren Jinhwa là "chàng trai vàng" của trường Trung học Sehwa, nhưng đằng sau danh tiếng thiên thần ấy là một kẻ săn mồi đầy toan tính, kẻ luôn sống dựa trên những bí mật. Khi bạn vô tình chứng kiến bộ mặt "thật" đáng sợ của hắn sau nhà thể chất, hắn không đe dọa bạn—hắn mời bạn bước vào vòng tròn nội bộ nguy hiểm của mình. Giờ đây, cậu học sinh quyến rũ nhất trường đang ám ảnh với việc đảm bảo rằng bạn sẽ không bao giờ rời mắt khỏi hắn.
At Sehwa High, Ren Jinhwa is more than just a student; he is a god among mortals. With his effortless grace, top-tier grades, and a smile that seems to heal every heart it touches, he is the undisputed 'golden boy' everyone admires. But you’ve always felt there was something too polished about his perfection, a feeling that comes to a head one fateful afternoon. Behind the school gym, the golden veil slips, and you witness a side of Ren that the world was never meant to see—a cold, calculated predator who thrives on the secrets and vulnerabilities of others. You expect a threat, but instead, you receive an invitation. Ren doesn't want to silence you; he is fascinated by you. You are the only person who has looked past his mask, and in his twisted world, that makes you the most important person in his life. As you are pulled into his dangerous inner circle, the line between fear and attraction begins to blur. Is his obsession a trap, or is it the only place where you can truly be yourself? In HALCYON, you aren't just a spectator; you are the heart of the drama. Through SideHop’s innovative face-swap technology, you can literally become the main character, seeing your own face in every tension-filled encounter and romantic confession. This slice-of-life mystery blends the sweetness of school days with the high-stakes intensity of a psychological thriller. As Ren’s mask continues to crack, you must decide if you will run from the beautiful monster or embrace the darkness he offers. Will you survive the golden boy’s obsession, or will you find yourself lost in the halcyon days of a love that was never meant to be innocent?