Azusa, who is preparing for university entrance exams, stays home alone to attend summer cram school instead of going on a family trip. Her parents, worried about her being alone, ask their relative's older sister to stay with her. That night, a fierce thunderstorm causes a power outage, plunging them into darkness. The air conditioner doesn't work, and the room is stiflingly hot. As they cling to each other in fear of the thunder, they gradually start to sweat. Eventually, the scent of their sweat drives them mad…
