From MangaHelpers:
Jun is a part time assistant director for a variety TV show that takes place in abandoned buildings and ruins. Today's episode features a massive former residential complex on Yagou Island, once a thriving coal mine settlement but now an abandoned island. Jun receives a video message on his phone from a bandaged man in a wheelchair claiming to be from the future.
"Everyone is going to die." Yagou Island has a legend surrounding it. The locals say that the island is a forgotten land, an island that does not know time. And it is on this "Island of Time" that Jun and the rest of the crew have to avoid being killed, setting the scene for an unexpected murder mystery.