Meh -_-'s manga / #Full Color(20)

The brother has more chemistry with the men. Unsurprising given how most romance MC & MLs have zero chemistry. I also feel like they made the brother straight because he was easier to ship with his friends (in no small part because they're all high schoolers & have established relationship dynamics that arent creepy or obsessive) than his sister. The MLs personalities revolving around her getting able to show other aspects of their personalities in his presence definitely helps. Also blue hair sucks. His personality is how his life revolves around the MC, nothing else. That's not just creepy it's obsessive & BORING. You can predict everything he says & does in her presence 10 chapters ahead.