He is the best brother in the world.
She is the best sister in the world.
They thought they would be together forever, but later, they separated.
This is actually an "ordinary" brother-sister love story that "doesn't matter if you think about it".
Some of the content may cause discomfort (although I did not write it directly), so please be prepared.
This story originated from a dream I had, which was a bit scary.
Conception:.