Akuru no Shima

The setting is Aonokushima, a secluded island in the Pacific Ocean, far from Honshu. Here, Reigo Murasame, a high school student, lives alone. His parents died in an accident, and his grandmother, who had taken him in to the island, also passed away recently. Yet, he has no plans to leave. He stays because of Ichika Kannagi, someone he harbors deep feelings for. One summer day, the two decide to attend a summer festival. Upon learning about a secret festival exclusive to adults, they venture into a restricted area deep in the mountains. Unbeknownst to them, this marked the beginning of a tragedy.