Nagata Ryuuhaku

Before the eyes of the protagonist, Harumichi Sai, his beloved girlfriend, Futaba Takanashi, is murdered. Harumichi is deeply hurt, both physically and emotionally, and becomes desperate. Just then, Harumichi receives a mysterious "key" in the mail. The key has the mysterious power to send its owner back in time to the past. ......

High scool student Goro who just thought "I want to get close to Kotone senpai who I love", visited an island where violent murderers from all over the world had been gathered. Can he and Kotone survive the Island?

A group of people have been mysteriously transported into a structure filled with deadly monsters. When they awake in this dangerous place, they remember little beyond their names, but they each also have a 'trigger.' Their trigger grants them an individual ability that will help them navigate through the dangerous area. Dan Hibiki wakes up and soon meets the telepath Hiiragi Sakura, radar-girl Misaki Haru, strong-man Kubo Taketo, and psychokinetic Fuse Yuuto. Dan's own ability seems to be to copy that of anyone he is near. They will have to work together strategically if they want any chance of getting out alive! \[tethysdust]. ————————- Woke up with no memories to a strange labyrinth. Countless monsters roam the corridors. A trigger that grants a special ability. Accept death peacefully? Scream for help? Or continue to fight? The most deadly fight for their survival begins!