In both of these series, guys get drawn into an alternate universe where mystical powers exist, and are left to fight for their lives.
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 stories are about guys who get drawn into an alternate universe, and are left to fight for their lives.