If anything doesn't match the original, consider it an author-added detail. Enter at your own risk: my writing is limited, and I'm a glass-hearted author, so consider this your warning. This is a free story, after all, so don't fall in love if there's no happy ending.
My wife, Chidori, has an older sister with excellent grades, the model student in everyone's eyes. But only Chidori knows that her sister, Yuno, is a psychopath, and that their parents' deaths were no accident. After Chidori graduated from elementary school, she and her sister stopped attending the same school. The official excuse was that Seagull Academy's uniforms were prettier.
Her sister was always grinning at her phone and often came home in the middle of the night. Sometimes, there was red blood on her clothes. But Chidori always played dumb and pretended not to know.
In her first year of middle school, Chidori accidentally bumped into her classmate Minamoto Kou, scraping his skin. As she tended to his wound, his blood rubbed off on her. From that moment on, Chidori's world changed.
Comment for yourself, this is a very quiet book, so quiet that the author wants to sleep forever.
The writing is pretty good 😄