Replacement

I'm late, but it seems like Hirofumi helped him after the death of the uncle. So, no, not really a replacement, but another form of emotional "support," even though their relationships are all toxic.

I agree. I don't feel any connection, nothing at all coming from Daigo, Hirofumi is merely a emotional crutch. Not that it's Daigo's fault since his "uncle" was the adult one and supposed to be a surogate parent and not a lover. Anyways not an ounce of romance, and forced to the point is such a bad story!