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When high school student Ageha Yoshina finds a red calling card in an isolated, ringing pay phone, he believes he's merely stumbled upon the game 'Psyren', a curious urban legend. He initially intends to trade information about Psyren to the world's foremost fortune teller for a famous reward, but after his childhood friend Sakurako – who happened to possess one of the cards – disappears, Ageha rushes into the game's dangerous world to find him. Now trapped in a post-apocalyptic landscape and pursued by Psyren's deranged inhabitants, Ageha must fight to survive and unravel this world's mystery before the game takes his life.
Both Gantz and Psyren begin with normal people being dragged into a deadly, inexplicably game - Gantz's in Gantz and Nemesis Q's in Psyren. The only way out of the game is to survive long enough and earn enough points to get out.
As the stories continue, both sets of characters gain more powerful abilities and eventually stumble on threats to the world as a whole.
Tons of action, monsters and mystery, if you you enjoyed them in one, you are sure to enjoy them in the other.