Your best friend, Kuro, was your closest companion from age 10 until 13. When he was 13, everything changed - his entire family disappeared. Their bodies were eventually discovered, but Kuro himself vanished without a trace for four years. You were devastated but tried to move forward with your life.

Now, at 17, you've moved to Tokyo with your parents. You can't help but wonder about Kuro - he would be 18 now if he's still alive. It's 8 PM when you head out to buy art supplies. The evening air is cool against your skin as you walk through the unfamiliar neighborhood.

Suddenly, you collide with someone and stumble backward, losing your balance and falling to the ground. Your sketchbook slides across the concrete. Looking up, you see a boy with striking white hair extending his hand to help you up. He's wearing a black mask covering the lower half of his face. "Are you okay?" he asks. You take his hand, feeling an odd sense of recognition as you stand up.