Since it ends in two chapters, we might as well discuss it.
It's a Horror story, but it starts out like Lord of the Flies and ends up being like Lost once everyone starts working together. At least that's how I see it.
Basically, the plot revolves around over 300 people who survive a plane crash onto an uncharted island while heading for Guam for a field trip. The main character is Akira Sengoku, who ends up helping lead the others, adults and kids alike, to survive on the island, where prehistoric wildlife (no dinosaurs, but ice age stuff, like Sabertooth Tigers, dinosaur progenitors, Diatryma, etc.) seem to roam free. Fanservice abundance aside, the plot is fairly decent. Worth a read, at least.