Persona 2/WMG

Who really killed Kashihara?
The unfortunate death of Mr Kashihara ten years ago was never fully resolved. Now, ladies, gentlemen, and anyone else who wants to come along, let us look at all the suspects and determine the murderer.

The Last Battalion: Hitler's contingent of soldiers that escaped to Antarctica after WWII. Accused by Mrs Okamura.
 * The case for: The Nazis also wanted to control the revelations in the Mayian Oracle and to keep their own existance from being leaked to the outside world. Though Kashihara had no desire to publish In Laqetti, they could still want some insurance.
 * The case against: They literally did not exist until the publication of In Laqetti made them real through the power of rumours. There's no way they could've done anything ten years ago. Okamura is crazypants.

Junko Kashihara: Famous actress and the victim's wife.
 * The case for: That Junko didn't care for her husband is a matter of public record. Trapped by a marriage to a conspiracy theorist husband who she thought was cheating on her...it's not hard to see how jealousy and rage could drive her to murder.
 * The case against: There's no hard evidence connecting her to the crime scene. Just disliking someone isn't enough to build a murder case around.

Maya Okamura: Fellow teacher with Kashihara and co-conspirator to write down In Laqetti.
 * The case for: Crazy and in love with Kashihara. On the testimony of one Detective Kuzunoha, Kashihara did not return said affections. Much like Junko, Okamura could easily turn to murder, and even has. She blamed The Last Battalion even though there's no way they could've done it; possibly delusions stemming from the dissonance of having killed the man she loved? She has means and motive.
 * The case against: But possibly not the will. Before her final breakdown Okamura really did want to see Kashihara live and protect the world from the dangers in the Oracle. She has the capacity to be a murderer, but perhaps she didn't then.

Nyarlathotep: Anthropomorphic personification of humanity's dark side.
 * The case for: He has the will, means and motive. Shapeshifting and teleportation alone assure an easy way to lure the victim and to get away afterwards. It was useful for Nyarlathotep for Kashihara to be dead for his plans, and he's never been shy about killing people for his goals.
 * The case against: Yeah, he pretty much arranged the whole thing. The ultimate cause of Kashihara's death is entirely the fault of the Crawling Chaos. However, it's not certain that he did the physical deed himself. It's just not Nyarlathotep's style to reveal himself openly until the end. Influencing people towards destruction and using catspaws is more his line, leaving the physical act to one of the other suspects. Also, it's difficult to arrest and hold anthropomorphic personifications.

Akinari Kashihara: World history teacher at Seven Sister's High School, the victim.
 * The case for: A wife that didn't love him and a son that was ashamed combined with a desire to save the school by preventing the Oracle make a strong case for a hopeless and desperate man ready to take his own life. The police at the time also ruled it a suicide, and hos ghost talks about 'wanting to be sure'.
 * The case against: It is not in the policy of this court to take the word of ghosts as evidence, and police have been wrong before. It's possible, even likely, that Kashihara killed himself, but we must look at all possibilities.

Colonel Mustard: In the hall, with the revolver.
 * The case for: After having murdered Mr.Boddy, the stubborn colonel noticed Boddy's associate Mr.Kashihara who met with Mr.Boddy regarding important business matters under the disguise of a business trip. Unfortunately, Mr.Kashihara saw just a little too much...
 * The case against: Doesn't exist in the persona games, but this is a series in which Hitler was a Mayan Sorceror armed with the spear that pierced the side of Christ so this theory can be plausible.

There is much evidence for and little against most of the suspects. What other wild theories may exist among the court? Speak!

Innocent Sin Online is based on Persona 2, and they take place in the same universe
We've just been playing the PS version. Whereas in P3 universe, the adventure became known at some point, and was recorded in Innocent Sin Online.
 * That...actually makes a lot of sense. What's the best way to prevent the people from Persona 2 from looking too deeply into those memories? Make them play it off as them being influenced by the game! Add in that Nanjou has the funds to push this game through, and it becomes even more likely!

Tatsuya is Naoya's son
He doesn't have a future in Persona, only a Shrug of God. This is more than likely.
 * How can Tatsuya be Naoya's son? Tatsuya's 18, and P2 happens 3 years after P1 ends.
 * And everyone gets a job and Brad becomes famous in 3 years.
 * True. (Um, now what?)
 * Actually, considering School Uniforms Are the New Black, it's more than likely that they weren't at school in the flashback. How long ago was it? Where did Naoya go? They seemed about 17 in Persona, so around 20 in the flashback. This means Naoya could technically already have a son, or could at least be a father that year, so as long as it was 18 years ago, this part of the theory is correct.
 * Except the returning P1 characters are all around 20 during the events of P2. (I'm pretty sure Nanjo and Elly are 20. Yukino might be a bit older.) Please don't make things up to support a jossed theory.

Ellen's Stalker is a distant ancestor of Mitsuo Kubo.

 * Both of them have no social skills, are Ax Crazy and have a similar appearance (though Mitsuo is somewhat neater and doesn't have the stalker's red eyes). Perhaps it's In the Blood?
 * Jossed. He's an illusion.
 * The stalker that appears in the dungeon was an illusion, but he was based on Eriko's memories of the actual guy.