It seems deliberately unclear on whether the current b-ko chan is the original playing-with-blocks one or the first double. Adds a layer of unsettling.

I think the implication is that she's the double, from the comment about how sometimes a copy would exceed the original. Which may mean the original hasn't died like the rest of the dupes.

Maybe a-ko chan is harboring the original b-ko chan at home; sister is a cover story

It seems deliberately unclear on whether the current b-ko chan is the original playing-with-blocks one or the first double. Adds a layer of unsettling.

I think the implication is that she's the double, from the comment about how sometimes a copy would exceed the original. Which may mean the original hasn't died like the rest of the dupes.

Maybe a-ko chan is harboring the original b-ko chan at home; sister is a cover story

Possible...im thinking A-chan might have the same thing but rather than killing they live as lije twins or something? But your censored theory would be cool ^_^

What the hell can't there be a normal doujin from this author? Is s/he Dowman Sayman 2 or what?

is not that weird i mean at least she/he isnt john k peta 2 that would be sooo much worse

"Shimazaki" "Supernatural" "Violence"
Oh boy

SHIMAZAKIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII

*first page
Huh, i think i have seen this art somewhere else
*"B-ko-chan"
oh, so THAT'S why weird shit is going on.

I'm guessing A-ko has a B-ko mutation living at her home.