Thats really wow good thing he ran away

Its kinda logical. He is the boy she always looked up to, willingly speaked to and thought was going to spend the rest of her life with. Justified or not, leaving without even a explanation to the sister that took care of you all her life is scummy.

wtf is actually happening?

Looking back at the other chapters, there are a lot of signs that point to her having an unhealthy obsession that I (and possibly many others) didn't notice.

Oh, that was just a dream, that is a relie...

nope, she is crazy

Cursed

Gizel-chan is scary. ROFL

Just say NO to incest!

Incest and yandere, this manga almost hit all my degenerate spots
If only author had pushed the 'less than five years from each other' part

@DFM1412 I get what you are saying, and I agree that it's... unpleasant, but the level of yandere she's started displaying won't be satisfied with that.
EDIT: What I mean to say is the story would probably just end if he did that.

@icarushector I know that, but atleast he can say he doesn't see her in romantic way or watsoever but has an option to be his sibling forever and give an illusion of being them living together forever to surpress that yandere side haha because honestly yandere imouto is a turn off.

@DFM1412 ... Uhhhhh, in that culture, "siblings" doesn't preclude "lovers", quite the opposite actually? Plus, if yandere is her natural state and not a result of the creepy black floater, a pretty standard response to rejection is "if I can't have you, nobody can".

I am really hoping that the yandere is a curable thing. I don't want the sister to be the bbeg of this series.

Manga: She really is a Yandere.
Me:

This could have been avoided if he said he wants to stay as siblings!!!! AAAAAAAA im scared for him

literally worst nightmare

Yep, this is definitely a white-haired Yuno Gasai.

Holy shit. Run farther. Or nuke the whole village.

@sonyalexandra It's a Japanese thing. Small children there often refer to themselves in the third person, so older female characters in stuff like this often do it to be cute. Cutesy might be a better word for it? If you did this in real life over there, you'd probably get bullied for it. I've actually seen that interpretation of this in other manga. A step further once or twice too, where another character specifically told the person doing this that it makes sense they're catching shit when they talk like that at their age like they're some character in a manga or something (kind of meta).

big yikes
the story could be way much better without that incest thing

YIKES