The protagonist, Tatsuya Suou, and a group of friends must confront a villainous figure called Joker, who is causing the spread of reality-warping rumors through the city.

Persona 2: Innocent Sin is a role-playing game where the player takes control of a group of high school students as they explore the fictional city of Sumaru.

These Persona summonings and fusions take place in the Velvet Room, a special location separate from the rest of the game's environments.

[9] A key element of the story is the Oracle of Maia, a prophecy foretelling of a series of events which will lead to the world's end during a planetary conjunction called the Grand Cross.

[9][10] The protagonist of Innocent Sin is Tatsuya Suou, a popular senior student at Seven Sisters who prefers to keep himself isolated from the rest of the school.

He joins with other students to investigate the happenings around Sumaru: Lisa "Ginko" Silverman, a Caucasian second-year at Seven Sisters who was raised in Japan, and Eikichi "Michel" Mishina, the second-year delinquent leader of Kasugayama High, as well as the adult Maya Amano, a reporter for a teen magazine, and Yukino "Yuki" Mayuzumi, a former student of St. Hermelin High and Maya's photographer.

Other important characters include members of the Masked Circle, a group influencing the rumors around Sumaru; and Nyarlathotep, a representative of the collective unconscious who acts in opposition to Philemon.

When Eikichi and his band do this, the Joker is summoned, then drains all the players but Lisa of their "Ideal Energy" (the essence of hopes and dreams) using a crystal skull.

They are eventually brought into conflict with the executives of the Masked Circle, a cult led by the Joker who are gathering Ideal Energy using assigned crystal skulls.

Ten years prior, Tatsuya, Eikichi, Lisa, and Jun were part of a group named the Masked Circle, where many of them sought solace from their awkward home lives.

In a tragic twist of fate, the deranged Tatsuya Sudou set fire to the shrine, and it was only Maya awakening to her Persona that saved her from death.

Jun, manipulated by Nyarlathotep into believing Maya had died in the fire, took on the mantle of the Joker to punish his former friends and make people's wishes come true.

With the Masked Circle and the Last Battalion waging war with each other, the party decide to return the city to normal by removing the five elemental crystal skulls being fought over by the two factions, then confront the Ideal Father.

On the way to collect the final skull from the heart of Xibalba, they are forced to stop Maya Okamura, a former colleague of Kashihara who has been driven insane by events, from fulfilling the Oracle.

The main staff from the previous game returned, including Kouji Okada (who acted as producer), designer Kazuma Kaneko, and writer Tadashi Satomi.

To emphasize his flamboyant appearance and link him aesthetically to the source of his power, Joker was clad in a strangely colored school uniform.

Due to the unexpected success of Persona's port, the production team was allotted a higher budget to work with, and they decided to use the additional funding to add more features to the game.

While he found the CD-based recording medium gave more freedom than the cartridge-based SNES, he had difficulties adjusting the pitches of overlapping instruments and managing memory space.

The new opening's theme song, "Unbreakable Tie", was written by Japanese hip-hop artist and long-time collaborator Lotus Juice and sung by J-pop singer Asami Izawa.

"[37][38] RPGFan's Neal Chandran was generally positive in his review of the PlayStation version, particularly noting how the characters confronted their past as well as fighting the main threat, and feeling impressed by the game's ability to move him despite him not understanding much of the dialogue.

[40] GameSpot's Peter Bartholow, reviewing the original, gave the game similar praise, saying "[Innocent Sin]'s story is darker, stranger, and more involving than most of the fluffy fantasy fare crowding today's marketplace.

[36] IGN's Vince Ingenito, while noting the game's differences from later Persona titles, called it "a wonderfully original story", and praised the localization.

[7] RPGamer's Zach Welhouse said that the game "uses its grand, cosmic backdrop to magnify the adolescent concerns of its protagonists until they pop with energy.

He further praises his characterization as being distinct from other examples of silent protagonists in the JRPG genre, exclaiming, "...unlike many angsty teens, Tatsuya is surprisingly likeable, pretty sociable, and many of his actions show strength of character".

[5] In his review of Innocent Sin's remake for PlayStation Portable, IGN's Vince Ingenito commented that Tatsuya's characterization, among the other playable characters, "creates a serious commentary on the average person's willingness to believe anything they see or hear while making teenage ennui manifest in tangibly dangerous ways", while also likening the game's overall narrative and portrayal of its characters, to an episode of the television series Buffy the Vampire Slayer (1997-2003).

[47] The gameplay was praised by Bartholow, calling the Persona system "Surprisingly simple and well balanced", and admired the game's polish despite its limited use of the PlayStation hardware.

[37] Chandran found many parts of the gameplay enjoyable despite noting the lack of its sequel's more autonomous Fusion Spells, saying that "had loads of fun playing [Innocent Sin].

[5] One of the Famitsu reviewers for the PSP remake was a little critical, saying that long load times when entering battles and the lack of guidance were among minor things that "niggled me".

[38] Petit was highly critical of the remake, citing the gameplay as "Tedious [and] repetitive", referred to the Rumor system as "dull", and generally felt that the game had not aged well.

[39] During the development of Innocent Sin, the writer Tadashi Satomi felt that the story needed an alternate viewpoint to that of the main hero.