It's kinda dumb, since it's from the viewpoint of a Koreimu.
To sum it up, when she's born, she can only think about taking it easy and getting sweets. Then she makes the mistake of saying so, and gets punished by her parent.
The mother tries to stop, but things escalate, with Marisa denying that Koreimu is her child... and eventually reaching the conclusion that any children born from Reimu is scum, and therefore should be killed. The thing ends with the Koreimu wanting to take it more easy and not understanding why something like that is happening to her.
Really, there are much more interesting stuff to read, such as the guy who punishes a Reimu by killing a whole bunch of other yukkuris in front of it while the victims' families watch from behind magic mirrors. If that Reimu apologizes for killing his Yuuka, he'd let them all off, but since Reimu was a shithead, all the yukkuris eventually come to two conclusions: 1. 'Mister human is too strong for yukkuris to defeat' and 2. 'That scum Reimu is responsible for everything'. Cue the yukkuri punishment and begging for mercy.
Ah this story sounds like it wasn't written very well anyhow. Thank you regardless. (you didn't have to go through the effort, a simple not interesting would have sufficed.)