Spoiler 

Ha-Yeong Yun is a top‑ranked student living in poverty, clinging to her grades as her only escape. Her longtime friendship with Yeon-U Seo, wealthy, kind, and effortlessly successful, has begun to rot with unspoken resentment. One night, Ha-Yeong finds an old phone and discovers it can show photos of the future. Using its predictions, she rises higher than ever before and grows close to Jeong-Ho Jeon, a charming transfer student. When Yeon-U reveals the phone is hers, Ha-Yeong lies without hesitation. Everything seems to be going her way, until the gallery updates with another image: herself, dead on the floor of her own bedroom. The clock in the photo reads May 17, 10:43 PM, five minutes from now.