It is about that I once watched an anime (I think I was probably not on Netflix) but forgot the name. It begins when a boy catches a girl who falls from a staircase, he notices that she doesn't weigh anything / only a little later you can see that she can kill with triangles or similar people without any problems, then go to a friend of the boy who the girl says he can make her weight normal
You definitely mean Monogatari.
"Bakemonogatari" from the https://de.wikipedia.org/...ari_Series
https://www.anisearch.de/...monogatari
The girl is called »https://www.anisearch.de/character/5181,senjougahara-hitagi«
The boy is called »https://www.anisearch.de/character/5174,araragi-koyomi«
Danke❤️
Bakemonogatari
