Marisa 's Cave

So...

Actually shadow silhouettes of coworkers weren't just a Teto's imagination or even hallucination. She's indeed works in a..unique company, which affects their workers in twisted way

How you could guess, this is a oil producing enterprise, which located in closed city in Japan.

Initially it was a secret researching laboratory, which had a goal to create a cheap and ecological alternative for oil. It's actually had some reasons.

Firstly, oil reserves were running out, and oil extraction made a huge negative effect on planet's ecology.

Secondly, first country, who would invent the solution, gets a big financial advance, so that was a concurrency race too.

Precisely because of this factor, scientists were trying to find easy and fast solituon, which created a quite hazard and toxic formula in process.

One day, one if their scientist, our infamous fan fanloid Akita Neru noticed symptoms of infection on her coworkers and..herself too.

Eventually, she find a way how to cure herself from it, cleansing her body, until it gets too late.

But her coworkers ended up having more heavy symptoms. They have been absorbing that oil so much, that their were turning into some kind of biological oil source, till they were dying.

Neru, instead of reporting about hazard danger, decided to take advantage of this situation, using her dead and half-dead workers as test objects and recourses, finishing the formula. But the experience of literally controlling those oil mutates she saved for better times..

She published her "invention". When government actually decided to found out about work process in laboratory, they closed their eyes on the incident, cuz Neru's formula actually could give them a lot of economical profit. Moreover, they hired everything and invested into laboratory, turning it into whole company with fabrics with secret closed city on their territory. Neru become a head of this company.

Yeah, I know there is a question, why not a Otomachi Una? Well..This goofy blobberry would get PTSD after just visiting company and finding out what actually going on there. Btw, if someone is interested, I could show later how two bosses meets up each other and how Una visits Neru's company..

Factory workers easily can be infected in work process, which turns them into oil mutants—creatures, whose flesh absorbed this toxic oil too much, uniting together. They're still can work, tho it affects their looks, turning them into those black silhouettes.

Office workers are intentionally infected through food and drinks, in which they add little bit portions of oil. Also local coffee's beans are made of oil and many other ingredients, so that's why caffeine smell is nauseous for Teto.

Neru uses condition of her workers in her advantage—when she "fire" mutant, it actually destroys their fragile body, turning them into oil pool, which she uses for sells. Such strict rules can force workers be more productive, do more as much value work for company as possible, so they wouldn't die in this concurrency.

[Don't worry,Miku is alive, this just example illustration by @marisiss]

What about normal people's reaction? They have been closed from normal civilization and brainwashed, like this is a hallucinations as consequences of living long time in a closed industrial zone with toxic environment.

The same story happened to Teto.

She have been fired from her last shitty workplace and she was failing in passing interviews to get job, no matter how much she worked for it.

One day, she got invitation from Neru's company(actually government sent her there. Something-something Beholder reference). When she has been accepted, she have been brainwashed too about hallucinations. Constant bullying, overworking and caffeine nauseous smell made her believe even more into it.

Department, in which Teto worked as intern, has their own story...

Everything started with Meiko and Miku. How we know, Meiko is a vocaloid veteran, so she got there job little bit earlier than Miku. Tho..Cause of Neru's false "sympathy", Miku got infected first cuz of her Boss' choice.

In this hierarchy getting infected means to be promoted. More you're getting oiled(oil concentration in the body ), more you're getting higher.

Meiko of course didn't know the truth, so she didn't like that Miku got promoted as boss' "pet", thought about her as plain person.

Moreover, Miku cuz of her cowardiness was working hard,so she quickly got highest rank. That's why Neru started to give Miku interns, and Meiko was her first subordinate. Meiko hated this fact and was angry at it..till she got infected and turned into mutant too. Tho, her opinion about Miku is still bitter, cuz she betrayed her, hiding the truth..

After it,Miku was getting more interns. They all created a whole department in which Miku was a head. You can see on image above chronology of workers being infected.

Mutation infected them in every ways. They become taller, changed partly biological and chemical structure of their body, but most important not only the body, but also their souls havd been rotted. That's why their tempers and attitude are so bad. Drinking coffee and lashing out on poor newbies are their coping mechanism. Tho, on one side, they're trying to fasten the process of infection, and on other side, they're trying to to push away newcomers in this way, to convince them without words that they need to leave here while they still have the opportunity. They're attitude is a both instincts and unconsious struggles to warn newbies.

Especially bitter feelings has Miku, cuz she have been forced to be quiet about the truth and see how are dying those people, who was relying on her. That's why she eventually give up, got cold and then worn out totally, lashing out on newbie just to feel anything alive. She feels like she sold her soul to Neru and this whole system.

Teto doesn't know about ANYTHING AT ALL. For her everything is like in canon, so the truth lurking somewhere, while she's cluelessly continues to struggle with ordinary problems in "ordinary" office....

Tho,sometimes she can suspect something and then get shutted up immediately.

But...

Her fate is inevitable.

In the end I can offer you thing about this whole story in metaphorical way. Think about it as irony for modern days, and as allegory of vocaloids story. Think, their boss is fanloid for certain reasons..

So...

Actually shadow silhouettes of coworkers weren't just a Teto's imagination or even hallucination. She's indeed works in a..unique company, which affects their workers in twisted way

How you could guess, this is a oil producing enterprise, which located in closed city in Japan.

Initially it was a secret researching laboratory, which had a goal to create a cheap and ecological alternative for oil. It's actually had some reasons.

Firstly, oil reserves were running out, and oil extraction made a huge negative effect on planet's ecology.

Secondly, first country, who would invent the solution, gets a big financial advance, so that was a concurrency race too.

Precisely because of this factor, scientists were trying to find easy and fast solituon, which created a quite hazard and toxic formula in process.

One day, one if their scientist, our infamous fan fanloid Akita Neru noticed symptoms of infection on her coworkers and..herself too.

Eventually, she find a way how to cure herself from it, cleansing her body, until it gets too late.

But her coworkers ended up having more heavy symptoms. They have been absorbing that oil so much, that their were turning into some kind of biological oil source, till they were dying.

Neru, instead of reporting about hazard danger, decided to take advantage of this situation, using her dead and half-dead workers as test objects and recourses, finishing the formula. But the experience of literally controlling those oil mutates she saved for better times..

She published her "invention". When government actually decided to found out about work process in laboratory, they closed their eyes on the incident, cuz Neru's formula actually could give them a lot of economical profit. Moreover, they hired everything and invested into laboratory, turning it into whole company with fabrics with secret closed city on their territory. Neru become a head of this company.

Yeah, I know there is a question, why not a Otomachi Una? Well..This goofy blobberry would get PTSD after just visiting company and finding out what actually going on there. Btw, if someone is interested, I could show later how two bosses meets up each other and how Una visits Neru's company..