Here is the full list of all 48 Persona 3 Reload achievements.
Unlocked a teammate's Combat Characteristic.
Defeated the Hermit.
Harvested a crop that you grew with a teammate.
Maxed out all Social Stats.
Defeated the Chariot and Justice.
Obtained an item from a Persona Conception.
Unlocked access to the remaining Major Arcana.
Nursed a cat back to full health.
Defeated the Hierophant and the Lovers.
Maxed out one Social Stat.
Maxed out one Social Link.
Rescued a missing person.
Performed a fusion with three or more Personas.
Spent an evening in the dorm with a teammate.
Used a total of 50 Twilight Fragments.
Obtained 10 Major Arcana during Shuffle Time.
Defeated the Empress and Emperor.
Ordered from a secret menu at the Iwatodai strip mall at night.
Aced an exam.
Opened 50 treasure chests.
Initiated 50 Chance Encounters.
Obtained 10 Personas during Shuffle Time.
Performed 50 All-Out Attacks.
Defeated the Priestess.
Triggered a skill change during fusion.
Defeated a rare, golden enemy.
Performed a Shift.
Performed a Dyad Fusion.
Joined the Specialized Extracurricular Execution Squad.
Obtained Orpheus.
Defeated Fortune and Strength.
Defeated the Hanged Man.
Sealed Nyx.
Watched the good ending.
Invited Elizabeth to your room.
Maxed out all Social Links.
Unlocked all Social Links.
Nurtured a romance.
Awakened all teammates' ultimate Personas.
Used all teammates' Theurgy.
Dealt over 999 damage in a single attack (All-Out Attacks excluded).
Discovered and conquered 10 Monad doors.
Encountered a Dark Zone in Tartarus.
Defeated the Reaper.
Fused Messiah.
Earned over a total of 50,000 yen from part-time jobs.
Accepted an invitation to hang out five times.
Acquired every Twilight Fragment in town.