In a mountain forest, a yukkuri family is living under tree roots. Marisa, Reimu, Maricha and two Reimyu (because we need one normal and one wasa for completeness).
They live happily. The children spend the day with their mother, waiting for their father to return from hunting.
Because the population are small, there's abundance of food. It also means the yukkuri doesn't form a clan, so the individual food gathering skill is very important.
Marisa happens to be a good hunter. She can gather enough food for her family everyday.
When Marisa went to her mushroom gathering site one day, she met a juvenile boar. Seeing the small size, Marisa thought she can win and got injured heavily by the boar (who seems to be conveniently there to hurt Marisa and went away with no reason after doing it).
Marisa, blinded and heavily injured, crawl in the forest without direction until she died rolling down a hill and crashed on a stone.
Reimu got little help from neighbour Alice, but they can't get food forever. Reimu decided to go to hunt on her own. Since she's relatively smart, Reimu kind of realized that Marisa is already dead, so she have to look for food for her children.
Unfortunately there's no food to be found.
Or more correctly, there's a lot of food, it's just that Reimu don't know they're edible and missed them. Reimu type are not hunter, they usually get married and just raise the children.
Reimu finally found a mushroom that looks like one Marisa took home the other day. There's a lot of them so the children would be very happy.
This is a grave mistake. Reimu only know this mushroom looks similar to the one Marisa brought home. It's actually a poisonous mushroom, lethal enough to even kill human.
While yukkuri, manju, should be immune against poison, their power of believe could make poison became even more lethal. Such as this Reimu who quickly vomitted and ooze out paste from her mouth and asshole until she's nothing but manju skin on pond of paste.
Maricha decided to go out to hunt. Unfortunately it started raining. Thanks to her hat, Marisa is protected, but the water will soak her leg and immobilize her. Quickly Maricha found a hole to hide from the rain and called to see if anyone is inside.
An Alice answered back and invited her in.
Right now, Maricha still don't know that there should be a special reason why an Alice would be living alone in such remote place.
Meanwhile, in their home, heavy rainfall cause the nest hole to be flooded, killing the two Reimyu.
Maricha is raped. Alice have a special medicine made of nectar and fruit juice she use to rejuvenate her victim so they don't die quickly. Maricha is raped again and again until finally she turned black.
Rain stops and Alice walks out her house, satisfied.
Then the mother boar happens to pass, crashed on Alice, and the raper explodes.
Just another day in the forest.