Corrupted Forest is a vocaloid fanfiction based off of the song "Trick and Treat" by Len and Rin Kagamine, and provides an origin story for the characters found in the song. It follows the lives of two prototype androids for the Kagamine twins, created in late October (of course). These androids are the first to be created by the company, Crypton, since their wildly popular idol android "Hatsune Miku," and are set to follow in her footsteps. They're very unsettling from the start, and the three scientists in charge of the project have wildly differing viewpoints on what to do with them. Dr. Kita, a severe woman in charge of the project, thinks that they are simply pieces of machinery who are meant to follow their whims. Dr. Chino, an older man who has been with the company since Miku, thinks that this is a dangerous attitude to take, and that the two wouldn't take kindly to being treated like they don't have feelings. Dr. Hiro, who is new to the company, is simply thrilled that the androids are functioning so fully.
As Len, in particular, behaves in a more and more unstable fashion, the scientists are divided over whether or not the project should be terminated before someone gets hurt.
The story, written in screenplay format, also has an extended universe developed through various roleplay blogs. A sequel origin story, developed by roleplay, may also be in the works involving Mayu, a yandere-themed android.
The Corrupted Forest screenplay contains examples of:
- Ax-Crazy: At the beginning, Trick and Treat mercilessly torture and murder Mary, their victim. Later, they slaughter almost all of the scientists at Crypton, with only Chino left alive.
- Came Back Strong: When the twins are incinerated by the scientists as failures, they come back with unnatural strength and senses.
- Creepy Twins: Len/Trick and Rin/Treat, in spades.
- Don't Go in the Woods: Or you might be sucked into an alternate dimension that houses murderous spirits.
- Elegant Gothic Lolita: Treat sometimes comes across as this.
- Finishing Each Other's Sentences: The twins do this a few times in the screenplay. More common in rps.
- Foregone Conclusion: The screenplay begins with the twins in the forest, luring a victim to their death. When their origin story starts, we already know what becomes of them.
- Kill It with Fire: The scientists try this with Rin and Len. It doesn't work.
- Meaningful Rename: After being incinerated and reborn, Rin decides that their current names no longer suit them. Seeing a Halloween banner, she decides that Len should be called "Trick" and she should be "Treat." They're referred to as such for the remainder of the story.
- The Smurfette Principle: Dr. Kita is the only female scientist on the team. After Rin and Len show their true natures, she admits that it was hard to get anyone to to get her seriously as a woman, and that she worked hard to get that leadership position.
- Trapped in Another World: Implied to be what happens to all of Trick and Treat's victims. People from any world can find themselves lost in their forest if they go out at the wrong time ... Even people from our own.
- Twin Telepathy: The twins seem to have several conversations without opening their mouths, and seem to know many of the same things despite never discussing them.
- Wide-Eyed Idealist: Dr. Hiro strays into this territory. He takes the longest to convince that the twins are beyond saving, and he forms an emotional attachment with Rin, truly believing that she would never hurt him. This ends badly.
- Wendigo: A bit of a different take on the lore. The twins seem to be related to the wendigo in some way, referring to them as "aunts" and "uncles" in the screenplay. It's implied that the Wendigo were created at the same time as humans, but were destroyed for being unnatural. Things with a soul could not be completely destroyed, however, so they wound up in a less-than-tangible realm. When the twins were incinerated, they met up with these creatures, but because they were destroyed by human and not deity, they were able to go back to a more solid dimension, a forest of their own. They are cannibalistic, however, keeping the main part of the mythos intact.
The Corrupted Forest extended universe also contains examples of:
- All There in the Manual: Anyone who hasn't followed the various rp blogs that led to the twin's development might become slightly confused if they were to ever read the screenplay.
- Genre Blindness: In most rps, characters saw nothing wrong with following two twins to their giant mansion in the middle of the dark forest.
- Schrödinger's Gun: Sort of. The idea of the twins existing in an alternate dimension that anyone could get lost in was created out of necessity when roleplay brought all sorts of characters into their forest, including copies of themselves and other vocaloids that didn't fit the decided mythos.
- Too Dumb to Live: So after everything that happened at Crypton, the scientists over at Exit Tunes decided it would be fun to make a robot specifically designed to murder everyone? No way that could go wrong ...