>>280614740
And the volume extra.

>>280615729
Not going to touch on the heart of it but if I'm answering it might as well be spoilered: It wasn't her primary intent but she couldn't resist. If you think about it, this of course spoils Onee-sama isn't surprised at the simple discovery of her imouto. After all what are the odds she'd be here by accident? Onee-sama isn't as scheming as Kasumi thinks, but it's fun how Kasumi's overthinking is so biased she misses the obvious. Even chapter 2 she never considered handwriting could be faked.

>>280615049
I'll marathon it once it's Ajisai's turn.