

Upon returning to the dorm in the evening, the player can opt to gather the members of S.E.E.S. During the Dark Hour, Gekkoukan High School will transform into a colossal, multi-floor tower known as Tartarus, considered a conduit for roaming Shadows. Outside of student life, the protagonist and their friends also operate as Persona users dedicated to eliminating the threat of the Dark Hour as members of S.E.E.S., thus presenting the portion of gameplay more familiar to traditional Megami Tensei mechanics.


A caveat to this portion of the game is that every activity the player chooses to do will consume in-game time and will take the protagonist's entire day to complete, thus forcing them to return to their dorm during the evening and putting emphasis on considering the importance or priorities behind particular tasks and how long a player should wait to complete them. Social Links can be maxed out to Rank 10, at which point the person in question may befriend or possibly pursue a romantic relationship with the protagonist if they are a female character. Chief among these activities is the introduction of the Social Link system, involving the protagonist being able to converse with select major characters they meet over the course of the game's story such as party members, as well as minor supporting characters with their own defined arc and personality. The protagonist has a set of three Social Stats: Academics, Courage and Charm, which can all be levelled up by either getting a part-time job or retaining a positive performance while in school, in order to improve their performance in day-to-day life while also opening up further options in regards to activities they can partake in or people they may converse with. Persona 3 is the first game to establish many of the series' mechanical and visual innovations from other titles in the Megami Tensei franchise, namely the integration of life simulation gameplay into the established RPG conventions of prior games. Persona 3 Portable is a role-playing game where the player assumes control of the main protagonist, a high school student residing in Iwatodai City on Tatsumi Port Island while attending a whole year of schooling at Gekkoukan High School. With this new power, the protagonist joins their classmates in forming the Specialized Extracirricular Execution Squad (S.E.E.S.), a discrete task force of other Persona users dedicated to the pursuit and elimination of Shadows and the Dark Hour phenomenon, while also intent on discovering the mystery surrounding its creation.

After being ushered in by their new dormmates at Gekkoukan High School, they awaken to their Persona, the physical manifestation of the soul, while also discovering that themselves and their dormmates are conscious during the Dark Hour as a result of possessing the "potential" to wield Personas. The protagonist, a transfer student returning to their birthplace Iwatodai City for the first time since the death of their parents, discovers a phenomenon known as the "Dark Hour", a pocket of time between one day and the next during which regular civilians unknowingly transmogrify into coffins while creatures known as Shadows roam the city.
