At least we always have Cabel. The one and only “brother” who actually sees her as a sister.
Little reminder that the title is "Be aware of the brotherS". And they have shown a lot of moments where Cabel scares other guys when he sees her sister in the knights training place. I am not so sure that he only sees her as a sister as well ... #－.－)
spoiler a bit
nope, based on novel cabel did see hari as a sister. When he know the relationship between hari and eugene, he throw a tantrum and try to avoid them.
Our blue haired guy had second ml vibes since the beginning but yeah like another comment said, it would be better if they showed the brother never seeing her as a sister but simply holding her dear to himself. It's also a bit sad the author decided to make the youngest brother love her too..one is enough and I wanted to see some innocent family bonding kind of love more...