This isn't anko2380; the anko doesn't have any pregnancy. But it does remind me of Yun Donuts.
Anko2380: Ride mister train easy!
Anon is heading to school on a train when he finds a family of yukkuri (Marisa-Reimu, with 2 Komarisa and 1 Koreimu) at his feet, apparently hitching a ride to visit an Alice they knew. One of the kids demands food noisily, and the parents feed it with stuff taken from garbage. It later poops, and when Anon moves his foot to avoid getting poop on it, he accidentally kicks another ko.
They make a fuss and demand that he kneel to beg apology, refusing a normal one. In the end, Anon is forced to give them all his sweets before they are satisfied, and they get off at their stop. Another commuter asks if he's okay, but Anon says he's getting off too, and gives up his seat.
He follows the family, and finds that they're living in an abandoned house. When they notice him, they initially sneer at him for being a glutton for punishment, but he kicks Marisa so fast that the rest of the family doesn't realize until he goes over to where Marisa landed after crashing into the wall and continues beating on her, stomping on the eye that popped out.
Reimu tries to apologize, but Anon tells her he wants all of them to die, and takes out the abuse stungun he bought just a while ago and zaps her. He then revives both parents with some orange juice, and grabs the koyukkuris and leave the house. Unexpectedly, the parents follow rather than abandoning their children.
Anon comes to a railroad crossing ties the Koreimu onto the end of the safety bar. While the parents try jumping to reach their kid as it pees on them in fear, he goes to buy a gas burner from a nearby convenience store. When he returns, he burns the feet of one Komarisa, then burns out one of Reimu's eyes when she tries to stop him. While Reimu is rolling around in pain, he puts the ko in the groove of the rail.
As a train approaches, the parents stop insulting him and beg him to save their child as Komarisa screams at its feet to move, but Anon tells them to try asking the train instead. They do so, and surprisingly, the train slows to a halt. Reimu takes the chance to try and pull Komarisa out, but she doesn't hear it warn that the train is starting to move. Marisa turns around to sneer at Anon, saying that the train is their ally... just as Reimu and Komarisa get run over.
Anon points out that it was only waiting for the right signal, as Marisa stares in shock at the remains. He then squeezes the remaining Komarisa, and tells Marisa to follow if she doesn't want it to die. Marisa is forced to leave the Koreimu behind, who is terrified of the next train coming due to the wind and sound.
Anon leads Marisa to a railyard, and ties her to the linking between two carriages of a freight train. He then rips out her hair to get her attention, and taunts her as he crushes the Komarisa to death in his hand. As he continues to strip Marisa bare, she uses the 'living' line, blaming him for kicking the ko in the first place, but Anon says that he doesn't care about that, and that it's her fault for daring to bare her fangs at humans.
He tells her he'll free her if she survives until the end of the train's route, and promises to kill the remaining Koreimu before he leaves. Injured all over, with no hair or accesory and missing one eye, Marisa can do nothing as the train begins to move and pick up speed.
A railroad worker finds Marisa during a stop check, and heals her with orange juice while wondering who did it. Revived, Marisa is revealed to have gone crazy from paste core damage, inflicted from traveling at speeds beyond 100km/h for the large part of a day. She runs off, and is found dead in the nearby toilet, having vomited out her paste.