Goro Akechi

"Have you finally pieced it all together? Case closed... This is how your "justice" ends."

- Goro Akechi, upon revealing his true colors to the Protagonist "Don't make me laugh! Justice? Righteous!? Keep that s--t to yourselves! You and your teammates piss me off!"

- Goro Akechi's villainous breakdown.

Goro Akechi is the (former) secondary antagonist (and one of the playable characters) of the video game Persona 5. He was a detective who is investigating the mysterious Phantom Thieves of Hearts case sensationalizing Japan. Akechi eventually joined the Phantom Thieves, despite his negative stance towards them and their activities.

However, it was later revealed that Akechi was a member of Masayoshi Shido's conspiracy, who joined into the Phantom Theives to orchastrate their downfall, but instead using this opportunity to get revenge on Shido instead when they outwitted his usefulness to eliminate his biological father. His true nature as a villain was not revealed until the climax of the game, although there are certain forshadowing in his true nature after his debut in the story.

He is voiced by Sōichirō Hoshi in the Japanese original and Robbie Daymond in the English dub.

Personality
Akechi is an ace detective who boasts a sharp wit and high level of intelligence. His aptitude for solving cases has him named "The Second Advent of the Detective Prince."

Despite his popularity, Akechi is actually quite lonely and yearns for attention and validation. He was abandoned by his father, Masayoshi Shido, lost his mother to suicide (which he later claims was the result of him being a "cursed child") and never had any genuine friends.

Several years before the start of the game, Goro offered his powers as a Persona user to Shido, who asked Goro to eliminate several major political figures who stood in Shido's path to securing the chair of Prime Minister. However, this was an underhanded revenge plot to get close to Shido and murder him after he won the election.

During this time, he mastered the use of his true Persona, Loki, and took down important figures connected to Shido by inflicting psychotic breakdowns; it is implied that he even killed Wakaba Ishiki, Futaba's mother, who was researching the Cognitive world for Shido. However, Akechi appears troubled while sitting in Leblanc the day after he shoots Okumura's shadow, signifying that he feels guilty about the crimes he has committed.

After Akechi joins the Thieves in an attempt to capture and eliminate their leader, he experiences how it feels to be bond with a group of friends for the first time, particularly with Ren. This leads to Akechi experiencing amibvalent emotions about disposing of the Thieves per Shido's orders. Throughout the game, Akechi remarks that there's "something special" about Ren, and he notes that they have a few things in common. Akechi simultaneously admires and envies Ren, who he later comments could have been "a great rival" or "a friend" if fate had dealt them a different hand.

After the Thieves defeat Akechi, Shido's evil cognitive version of Akechi appears and reveals that Shido knew Akechi's true identity from the start and has planned to kill him after the election. The Cognitive Akechi demands that the real Akechi shoot the protagonist to spare his own life. Akechi redeems himself by sacrificing his life to save his friend -- he shoots his Cognitive double, then seals himself and the double behind a steel barricade. Smiling sadly, Akechi asks Ren to take down Shido in his stead. With this, Akechi and the protagonist's "desires become one."

Trivia

 * Despite being the game's traitor and red herring, Akechi placed 1st in a poll for the most popular member of the Phantom Theives of Hearts.
 * The fandom often points out how Akechi bears a physical resemblance to Light Yagami.
 * Unlike Light, who never atoned for his wrongdoings and died trying to escape imprisonment, Akechi expressed remorse for his actions and sacrificed himself for the Thieves.
 * Fun fact: Ryuji Sakamoto's seiyu, Mamoru Miyano, also provides the voice of Light Yagami. 
 * Akechi is often compared to Ken Amada, a party member from Persona 3. However, his guest party role is more similar to Shijiro Aragaki due to both sacrificing their lives saving their true friends from being killed by the main villains.
 * Akechi is somewhat similar to Tohru Adachi, the former main antagonist of Persona 4 turned protagonist of his arc in the fighting game sequel Persona 4 Arena Ultimax. Both started out as supporting characters before they were revealed as secondary antagonists. They share the same abilities as the protagonists -- Izanagi for Adachi and Yu Narukami, and the power of the Wild Card for Goro Akechi and Ren Amamiya. Later, both Akechi and Adachi redeem themselves.
 * Akechi's Arcana is Justice, but his true personality matches that of the Reversed Justice Arcana. Like Justice Rx, he is dishonest about his intentions, exhibits black and white thinking, and unfairly manipulates rules and authority figures to achieve his goals. On a deeper level, it also points to the injustices Akechi has faced as a victim of his father's neglect and Japan's corrupt foster care system; these injustices led Akechi to lose faith in society.
 * Although not stated officially, it is highly implied that Akechi represents the sin of despair/emptiness (Latin: Cavum), also known as acedia, which was originally considered one of the deadly sins until it was merged with sloth. Akechi explains that he was born an illegitimate child to a mother who later committed suicide, and he grew up lonely and unwanted. As a result, he tries to assign meaning to his existence by being popular, successful, and 'special.' He obsesses over enacting vengence against his father, whose rejection is a major cause of his emptiness, no matter the cost -- even to the point of feeding into Yaldabaoth's game and committing murder.
 * There are many instances throughout the game that foreshadow that Akechi is the traitor:
 * When first meeting the Phantom Thieves, Akechi mentions 'delicious pancakes'. The only one who had talked about eating pancakes is Morgana (he compared the Dome Town Stadium to a pancake); only those who have heard Morgana speak in the Metaverse can understand him in the real world.
 * Although Akechi appears on the title screen and cover, he is the only party member who doesn't appear in the opening. Metawise, he is also the only party member to not have their own commercial. He does not appear with the rest of the party on the reverse artwork for the game's Steelbook Edition or on the collector's box for the Premium Edition.
 * The Phantom Thieves always refer to him by his family name. Everyone else who joined the group is addressed by their first name.
 * When Akechi runs into the Phantom Thieves at the school festival, the first thing he says is, "Oh, everyone's all here," as if he recognizes them -- despite the fact he has only seen Futaba Sakura with the protagonist and has never met Haru Okumura. Futaba catches onto this.
 * Akechi is the only party member who wears gloves while in civilian attire. His gloves are befitting of the elegant image he presents to the world, but they also proved useful for Akechi when comitting crimes, such as attempting the staged murder-suicide of the protagonist. (He succeeds in the bad end).
 * Akechi's Persona, Robin Hood, was a rebellious figure like the other Thieves' Personas, but he is usually depicted as swearing his allegiance to the crown following King Richard's return. Akechi is later revealed to be the traitor and working for Masayoshi Shido, a powerful political figure. Similarly, Akechi's true persona, Loki, is often portrayed as a malevolent trickster in mythological lore; the Phantom Thieves' Personas are portrayed as anti-heroes, at worst.
 * Robin Hood is almost universally portrayed as wearing green, yet Akechi's Persona wears white. While it does appear more fitting for the superhero's princely design, it also symbolizes Akechi hiding his true colours from the Phantom Thieves and the world.
 * Goro joins the Thieves near the time of the Casino Palace heist, where Joker is successfully apprehended. The ambush is Goro's idea, and he uses leverage to prevent the party from backing out.
 * He insists the Phantom Theives raid the Casino on a certain date, unlike every other Palace thus far, because he planned the ambush for that day.
 * If the player fails to complete a Palace within the time limit, the protagonist incorrectly recalls what truly happened due to the high dose of sedatives he was adminstered in custody. After Sae ends the interrogation and leaves the room, the traitor appears and kills the guard and shoots the protagonist point-blank. The shooter is holding the gun in their left hand; Akechi is the only left handed member of the party.
 * While Akechi is speaking as a guest of honor at the school festival, Yusuke infers that if Akechi believes the Phantom Thieves are dangerous yet innocent of murdering Kunikazu Okumura (and others), then he must either know the true culprit's identity or the identities of the Phantom Thieves.
 * Akechi catches on to how the Metaverse works very quickly while in Sae's Palace. The party pretends to write this off as a result of him being a detective, but even then, he seems too comfortable for someone who claims to only have only ever been inside one other Palace. This is made more suspicious given how Makoto and Futaba, who are around Akechi's level of intelligence, still took some time to learn how the Metaverse worked and even needed guidance from Joker and Morgana.
 * When the Thieves first enter Okumura's Palace, Akechi is secretly observing them in the shadows. Akechi claims he was following the Thieves and accidentally got sucked into the Metaverse, awakened his Persona, then obtained photographic evidence of the Thieves' existence after they returned to the real world. However, later revelations of Akechi being the Black Mask strongly imply that he had deliberately infiltrated Okumura's Palace in order to stalk the Phantom Thieves and assasinate Okumura once the Thieves had defeated him.
 * Joker can use the school library to check out books about the historical figures his teammates' Personas are based on, but a book about Akechi's Robin Hood is never available.
 * Initially, after his boss battle, Akechi would have return back to the party and helped the Thieves again by using both Robin Hood and Loki as his Personas (both playable), which could switch between each other like all of the protagonist's Personas. However, this idea was scrapped and Akechi's ended up sacrificing himself. Although, his apparent death scene was not presented onscreen, leaving his fate unknown. Additionally, if you fail Shido's Palace after Akechi's death, Akechi will still appear to kill the Protagonist like he does for all the other Palaces- however, the dreamy filter applied to this sequence leaves it ambiguos as to whether or not it's even happening.
 * In spite of this, there are mods for the game to make Loki a playable Persona.