GANTZ - S01

Knowing his life is on the line, Kei Kurono does something out of character and jumps onto the train tracks to save a homeless man from death, only to die himself. But when he wakes up, Kei finds himself in a room with several other people who have just died, along with a large, mysterious black ball. As everyone in the room tries to figure out what is going on, the ball suddenly opens, revealing a stash of weapons and strange black suits. The ball then tells them they have to hunt down an alien and teleports them to an unknown place. With almost nothing to go on, Kei teams up with his childhood friend Masaru Katou and a woman he does not know, and the three of them explore their new surroundings. It quickly becomes clear, though, that they have stumbled into a dark and dangerous world where anything could happen to them.