>>57
I thought most of the MPD Psycho story so far has been pretty straightforward but long. Though, it helps a lot of if you read it all in one-shot. I'll try to give a summary, but it's been a while since I've read it so some points may be wrong. Spoiler warning follows.
The basis is that Lucy Monostone is considered the ultimate killer, that he has the best genes and personality. The ultimate goal is to recreate him. Everything revolves around this. Gakuso itself is an 'underground' government organisation formed before WWI with the aim of creating a pure Japanese race through manpulating genetics. After the war, the US took over and continue to fund it with other intentions.
Lucy Monostone is the original founder of Gakuso. One of the other founders is that old guy that talks with the PM and later on with Kitou in v10 but it's been hinted that he had slightly different intentions for Gakuso so that's why he's been sort of aiding some of the 'good guys' (very relative term).
Anyhow, it's also been hinted that Gakuso does a lot of things with genetics. Of them, include creating genetically modified babies have a sort of 'buffer' space in their genes and can use visual stimuli to read and write into that buffer to change their personality. They are also 'modified' to more readily support multiple personalities. Yes, I'm fucken serious. That's how all the personalities are being swapped and transferred. These manufactured children all have the barcodes on their eyeball.
Their other focal achievement, is creating body doubles for everyone in the shadow cabinet and all the crucial supporters of the current PM. Body doubles in the sense of people that have the same DNA so that if something happens to the original, these people are killed and their organs are used. IIRC, at the beginning he was some sort of minister and manipulated events via Gakuso to work his way up. These body doubles are believed to have been created for most of the barcode children as well but I don't think all.
I'm a bit unsure about Lucy Monostone's personality program as it's more implied than spelled out. But I think the Lucy Monostone personality cannot be recreated wholly as one but rather as a composite of key multiple personalities. These personalities are the ones that were at the orphan where Amamiya, Kobayashi, Nishizono, Murata, etc. lived. The orphan was a setup by Gakuso to develop the personalities for the Lucy Monostone reconstruction. This is pure speculation, but I think the whole fire and the convergence of all the personalities into one kid was predicted by Gakuso.
Most of the early MPD Story is about how the person carrying those personalities rediscover himself and again, this is speculation but I believe this is a controlled event by Gakuso using the one-eye reporter guy as a proxy.
Kobayashi is the gentle police-dude personality that took over after the fire. Amamiya is the smart but passive personality that takes over after going into jail and for most of the time before he disappears. Nishizono is the personality that takes over and kills people. He showed up when he killed the killer of the girlfriend and is the one that took care of all the serial killers they investigate in the beginning.
The Nishizono he has is not complete though, Machi's sister has the other part. The Tetora kid has a part of the Nishizono personality as well. Eventually, the Nishizono personalities all realise they need the Amamiya personality for their existance. The whole v07 is about those parts all coming together. Also in that volume, the original Amamiya body is destroyed and his personality is transferred to the Tetora kid.
Tetora himself is not a 'perfect' body so he can't keep all the personalities inside him. He uses drugs to suppress Amamiya's personality. He also made a promise with Machi's sister to not let Amamiya's personality die so he's in survival mode until he can pass on the personality to a better host. He also has a bit of bad taste with Gakuso so once he gets the 0 pill that cures him of his dependence on Gakuso's drugs, he starts killing their body doubles. v10 is about the PM using one of his body doubles and a revelation that Machi herself has an alternate personality.
I'm probably missing a huge arc but that's all I remember at the moment. So in summary, the story is about an organisation that has created people who have multiple personalities and can transfer them around. Some of these key personalities combined can be synthesised into Lucy Monostone, their ultimate goal. The organisation is involved with power plays between the government, itself and some splinter cells. Everyone's ultimate goal is to synthesis those personality themselves and then control that one personality.