While it is refreshing to see the inverted equivalent of that slow-life manga where all female chars steal others stuff and the mc is continually physically abused by everyone, this is also annoying me for the very same reasons that one does. Although I am at least happy that author is very much aware how perverse the idea of an adult brother traumatizing and abusing his single-digit old sister like this is.
I really hate the fact that I bet the author intends to give the brother some chapters to "redeem" him in the eyes of the viewers, glossing over the abuse as ok through humor, as is always done in those situations.