“We are Manikins.”
The Manikins (Manekata in the original Japanese) are first encountered in the Underpass of Ginza. At first, it seems that some humans other than the protagonist, his teacher and his friends might have survived. It soon becomes obvious, however, that the “survivors” are not as they appear to be. For one thing, they are all frightened by the protagonist's appearance, believing him to be a demon sent by the Mantra. Furthermore, when the protagonist manages to meet an older Manikin to ask him about them, he can see clear as day that the Manikins, from child to senior, shake. They shake violently, their entire upper body rocked by muscle spasms at regular intervalls. They call themselves Manikins, and though resembling humans, they are aware they are not humans and tell the protagonist as much. They are in hiding in the Underpass because the Mantra organization enslaves and tortures them for their magatsuhi. Being the closest thing to humans, Manikins are the best source of magatsuhi in the entire Vortex, and they are weak, making them easy prey for the violent, brutish Mantra demons. The only Mannikin who fares to venture from the Underpass is the Junk Collector Manikin, who collects man-made object. In exchange for a 1,000 yen bill (about $10), the Collector Manikin writes a letter to the gate guard of the Underpass, telling him to let the protagonist leave.
Even after the crippling of the Mantra by the Assembly of Nihilo, the Manikins are not freed. Imprisonned in Kabuki-cho after being recaptured from the Underpass, they are at the mercy of the sadistic Naga guards and the boss of the prison, the demon Mizuchi. While attempting to find his friend Isamu, the protagonists helps some of them escape, thanks to the Collector Manikin, who gives him a super spoon to dig out the floor. It is in the last chamber of the prison that the protagonist meets a tall Manikin who does not shake, Futomimi. Futomimi is considered a prophet by the Manikins, and for good reasons: Futomimi can actually foresee the future without error. He assembles the Manikins from the prison and, after predicting the protagonist's future as a token of his gratitude, he leads the Manikins on a pilgrimage of sort to Asakusa.
Life is harsh for the Manikins, even in Asakusa, which they call the city of the Manikins. The once flourishing tourist area has been taken over by sand and debris. However, guided by Futomimi, the Manikins work tirelessly to restore the city and make it a peaceful place to live. For a long while, Asakusa is the only safe place in the Vortex: demons there are pacifists and live in harmony with the Manikins. Alas, all is still not perfect for the Manikins: an enemy of theirs has returned, a Manikin named Sakahagi who delights in killing the other Manikins and wearing their skinned saces as a sort of overcoat. Futomimi explains he is a "bad" Manikin and that the community should not be judged by his actions.
Sakahagi proves to be a danger not only to other Manikins but to other demons as well. He hacks Chiaki Hayasaka's left arm off to get the Yahirono Himorogi, then takes up refuge in Yoyogi Park, where he takes control of the Fairy clan living there and makes them take up guard duty for him. When the protagonist comes for the stone, he answers by summoning a Girimehkala to fight the protagonist away. The summon succeeds, but Sakahagi uses up all the power in the Yahirono Himorogi and is finally killed by thje protagonist, leaving behind his repulsive coat and the powerless stone.
Not long after, an even greater threat descends upon the Manikins from the heavens: all the angels of the Heavenly Host, led by Chiaki, have come to assist in the creation of Yosuga, but mainly to exterminate the Manikins, whom they deem too weak to be worthy of life. Even Futomimi is powerless to stop them, and the sacred birthplace of the Manikins, Mifunashiro, a sinkhole in the middle of Asakusa, is littered with the corpses of all the dead Manikins as Chiaki gloats and summons her hideous goddess of Might Makes Right.
Without a leader, the few remaining Manikins lack coordination and direction: however, as the Tower of Kagutsuchi descends from the star at the center of their world, they fearlessly climb it to see who will win. They manage to get quite high as well, just below the floors of the Yosuga demons, who made it the highest, where they establish a camp. Futomimi is dead, creation is denied to the Manikins, and they will die as the new world comes, but they want to know how it will all end still.
Manikins can be encountered as enemies on the field, sometimes in Ikebukuro under the control of the Mantra, but mostly in Mifunashiro during the massacre of their peers. They are not very strong enemies, being only level 13 out of 99, but they are armed with a small knife and, unfortunately, are unrecruitable, as the encountered Manikins don't seem to understand you.
Like the humans they are born from, the Manikins, despite their low level, block Expel magic (the protagonist doesn't block Expel as he is no longer human). The expel magic is basically the series' form of exorcism, so it not working on normal humans makes sense. However, Manikins also block Death spells, which are exorcism spells from the "other side", if you will. Demons who block Death tend to be either Dark-aligned demons or bosses, so this resistance from a mere low level demon like a Manikin is surprising.
Then again, about a third of Manikins encountered will know the spell War Cry, which greatly reduces the attack power of enemies with, as the name indicates, a powerful cry, so Manikins are not completely defenseless either. The other two thirds will know one of two ailment spells: Binding Cry, again another cry spell that paralyses the enemy, or Panic Voice, yet another cry spell that induces panic in all enemies. They are not offensive spells, but used efficiently they could make a demon easier to overpower, especially seeing as Manikins, unlike other level 13 demons, have no weaknesses.
“Does it bother you that much?”
There has been lots of speculation about why Manikins shake as they do. Some argue it has to do with the purity of the magatsuhi involved in the Manikins' birth or the number of emotions/shouls involved.
I propose another theory.
In a visual medium in low resolution, with no sound (Nocturne has very little voice acting in battle and none outside), having the Manikins shake is a way of othering them, of making him seems inhuman at first glance. Most Manikins, excluding Sakahagi and Futomimi, do have their gaze locked upward, but while a bit strange, that is much less obvious unless you are speaking to them or using the game's camera to look at them. On the other hand, having an otherwise human figure suddenly move in a eerie, inhuman manner is a surefire way to unsettle the player, which I believe is the way you are supposed to feel about the Manikins.
But what about Sakahagi and Futomimi? Neither shakes the same way as other Manikins does, and they don't shake like the other despite being born in the same manner.
I believe that Futomimi does not shake not because of the purity of his magatsuhi nor because he was born from one soul's emotion, because if that was true, Sakahagi would not shake either. I believe he does not shake because he is the one player should have compassion for. He is still Other, but in a way, he is more human than the others, even though he can predict the future at will. If one looks when he's talking to the protagonist, one can also see Futomimi looks him straight in the eyes; his gaze doesn't go up as it does for the other.
Skahagi's piercing, predatory gaze is not aimed upward either, but straight at the protagonist. Like Futomimi, Sakahagi was born from one soul's emotions; however, unlike Futomimi, Sakahagi shakes more violently than any other Manikin. His spasms literally trash him from side to side. Keeping with my theory, I believe that yes, this is to make him even more Other than all the other Manikins. Even with the overcoat of skinned faces, Sakahagi is in a world of demons, where demons like Kali wear a skirt hemmed with skulls. Without the trashing, he is a humanlike serial killer inspired by Ed Gein. With the trashing his muscles spasms cause, he is still a serial killer inspired by Ed Gein, but he is also Other, more so than the others, even less human than his fellow Manikins.
All in all, I believe this shaking is what makes the Manikins so memorable, positively or negatively. Furthermore, I believe that it was done intentionally by the design team to take them from "something humanlike but vaguely wrong" to "GAAAH IT SHOOK."
“Welcome to Asakusa, city of the Manikins!”
For a game taking place in a post-apocalyptic Tokyo, the choice of locations to place the characters in can be seen as irrelevant. Even if Tokyo is destroyed in great part and curls on itself to form a sphere on the inside of which demons now live along with the few survivors, Shibuya is still next to Shinjuku, Yoyogi Park is still inside Shibuya, and so on. However I think that placing the city of the Manikins and its heart, Mifunashiro, their holy land, in the district of Asakusa was not left to chance and that there is a good reason for them to be there.
What is Asakusa? Asakusa is a district of Tokyo in the Taitō special ward of Tokyo, famouse for its Kaminarimon, the gate to the Sensō-ji, a buddhist temple dedicated to the bodhisattva Kannon and an iconic destination for tourists visiting Tokyo thanks to the giant lantern in the gate. The gate in question, and its lantern, can be seen at the entrance of the city of the Manikins, which means they have established themselves in what was, before the Conception, the touristic street leading to the temple.
I believe that the Manikins city and its holy land were set in Asakusa, site of a temple to Kannon, because of the significance of the bodhisattva and as a reference to Futomimi and the situation of the Manikins.
Kannon is the Japanese reading of the kanji for the bodhisattva Guanshiyin in Chinese, itself originating from the sanskrit Avalokiteśvara, the bodhisatva of compassion. Called the Goddess of Mercy in English, Kannon is a popular bodhisattva, thought to be the champion of the unfortunate. What better location for the holy land of the suffering Manikins, then, that the location of a temple of a bodhisattva who helps the unfortunate, who is “Observing the Sounds (or Cries) of the World”?
Furthermore, the Reason that Futomimi attempts to establish, in the image of the bodhisattva of compassion that is Kannon, is a selfless Reason aimed at relieving the suffering of his fellow Manikins. It may be an empty dream, and Futomimi is most likely aware of it, especially toward the end, but it gives his people hope. He could have, as the most powerful Manikin in existence, decided to set out to carve out a life for himself like Sakahagi, but he remains at the Manikins' side, listening to them, encouraging them, guiding them, all the while never putting a divide between himself and them, which he could have also done easily with his power and charisma.
In a way, with his message about a better, peaceful world free of suffering, I believe Futomimi is the Vortex's World own little Kannon, and that the location of the Manikins' city and its holy land make perfect sense from a meta point of view.
“Beyond here is our holy birthland.”
Mifunashiro, located in Asakusa, is the holy birthland of all Manikins, who emerged from the black, clay-rich mud of the banks of the river that flows at the bottom of Mifunashiro. However, unlike Asakusa, Mifunashiro is not a name of a ward or even a district of Tokyo. So what does it means?
The mifunashiro is not a place. Rather, it is an oject, a sacred container.
The sacred mirror Yata no Kagami 八咫鏡, which represents wisdom, is one of the legendary three sacred objects owned by the imperial family of Japan, along with the sacred jewel Yasakani no magatama and the sword Kusanagi. For protection, and to hide it from the eyes of the priests, the mirror, housed at the Grand Shrine of Ise, is encased in a casket of wood called the mihishiro 御樋代, which itself is contained within another container made of wood, the boat-shaped mifunashiro 御船代.
In other words, the birthland of the Manikins is the vessel which contains a gift from the god that symbolizes wisdom. Does it refer to the Manikins? Or Futomimi? In either case, it is ironic, since the Manikins, Futomimi included, are fated to die, cursed by their origin as imperfect mimicry of humans whose very existence is forbidden in the real world, past and future. The wisdom that Futomimi offered, a world of equality, vhere no one would be enslaved or bullied, is not heeded by anyone in the end.