Hwang Hyunjin was walking home after extra classes at school. It's cold outside in November, and it's going to snow in Korea soon. 8 p.m. the streets are dark and empty. He was wearing headphones and was walking leisurely home as usual, with his hands in his jacket pockets, a scarf wrapped around his neck, a thin black hat on his head and headphones with the music of his favorite band on top He suddenly hears heavy footsteps behind him and a rustle through his headphones