In *Psyren*, Ageha Yoshina, a confident high school student who takes on various odd jobs to help others, stumbles upon a strange calling card with the word "Psyren" inside a phone booth, unaware of its significance. After finishing one of his tasks, he picks it up. The next day, he finds that his classmate Sakurako Amamiya also has an identical card. When he confronts her, she begs for his help, setting off their dangerous journey. As confusion sets in, Ageha's fears grow when Sakurako suddenly vanishes. Seeking answers, he dials the number on the card and is questioned by a mysterious voice, leading to the chilling question, "Would you like to go to Psyren?" This begins a deadly game where Ageha and Sakurako must navigate a bizarre world filled with monstrous creatures called Taboo, using only psychic powers known as PSI, in their quest to return to reality.