I know I am in the minority with this but... I never saw them as love interests.
I know he had a crush on her, but for the whole of the story, I always felt Yakumo had too much baggage for a boy like him, and to me, the story had more of a "found family" vibe.
Before someone says... no I didn't ship him with his friend.
I am... kinda disappointed that the author did this extra.
And the funny thing is... just a few hours back I thought about this series and decided to give it a reread, then i update my follows list and here it was this extra.
Oh well, it is what it is, happy new year yall.