Similar to the original manga, the new series focuses on Naraka High School, an institution that accepts only students capable of seeing an island in the sky. Although it is purported to be a prestigious school where graduates are assured of excellent government positions, the students are compelled to fight for their survival in order to graduate. The new protagonist is Hiroshi, a 15-year-old boy who can see the island in the sky. He and his friends enroll in the school as a test of courage, but he is the only one who returns.