Wow this is reaaally twisted and creepy. XD
No, this is reaaally cute and adorable.
I do have a quibble, however: I find the imouto character difficult to understand.
I had figured, from the title of the manga, that imouto-chan had already noticed her oneechan's secret feelings for her - and was totally ok with them! However, the more I read, the more oblivious she seems. Um, wtf?
Could it be that the author has decided to rewrite her as some sort of pure angel who is completely unaware of Shima's siscon?
If that's what it is, it kinda sucks.