The last pair from the latest chapter is the teacher who rebuke Taiga because he sees the resemblance to his brother.
Remember he was said to quit being a teacher? Apparently he was 'confined' by the step brother. The step brother loves him to the point he ruin the brother by 'breaking' him, isolating him from the world except him(the blonde guy)
From past chapters, what I can inferred is that the step brother loves him since child and make moves on him during high school. The brother may like r may not actually like him, but because the blonde is his brother who is 'closest' to him but having a twisted love makes him the 'furthest' (applies to both sides, I guess).
In short, the step brothers have a twisted toxic love relationship.
Thank you for clearing it up.
In the latest update the last panel or the last pair. Who are those guys? I really don't remember their involvement in the story. can someone help me to understand who those 2 step brothers are