Chapter 9 : "No need for rivals, because everyone read this for the romance between the sister and the brother ! Others girls are annoying because you have less scenes between the main couple !"
Chapter 10 : Add another useless filler girl
...Tell me it's a joke.
And it's not only because they're rivals, it's because every other girl so far are a very poor characters.
This story would be much better without this forced harem.