Persona 2: Innocent Sin takes place a few years after the original, but focuses on a new main character called Tatsuya. The latest urban myth is that calling your own cell phone number will summon "The Joker", who will grant you a wish. When Tatsuya and friends try out calling the Joker, he appears and seems to bear a grudge towards Tatsuya, taunting him about a sin he can't remember. He later meets Philemon, who grants personae to him and his friends, much like the original, and they begin their journey to discover the meaning behind the Joker's words.
This game is also known as Persona 2: Tsumi in Japan.