Takashi Mitsuya/Relationships

Yuzuha Shiba
Yuzuha and Mitsuya seem to have a neutral treatment before the Christmas conflict. Although Yuzuha seems to feel a little jealous of Mitsuya as an older sister, because Hakkai prefer to have Mitsuya as a wallpaper on her phone instead of her (as Yuzuha, who has Hakkai as the wallpaper on her phone).

Throughout the Black Dragon arc, Mitsuya has knowledge of how abusive Taiju Shiba is. And he decides to help Hakkai prioritize Yuzuha's well-being by allowing Hakkai to leave Toman on the condition that Taiju will not hurt Yuzuha further.

Later during the Christmas Conflict, after Hakkai confessed that it was him his sister was actually protecting from Taiju, Mitsuya apologized to Yuzuha, due to the strong expectations he had instilled in Hakkai on how to be a brother and that It led him to lie. Considering then that he wasn't as good a big brother to Hakkai as he thought. Mitsuya concludes that apology by expressing to Yuzuha that she respected her.