I've been mulling over this since the chapter came out and I still don't quite understand what everyone is so worried about... All I see here is an extra chapter that expands on Niibashi as a person, his feelings and why he's so willing to lend Kagi an ear when he needs it. It doesn't read to me like he has feelings for Kagi or anything if that's what people are assuming, I get the impression he's just grateful to have a friend who understands/accepts that while Niibashi can be harsh, he doesn't mean any harm by it. Well, I'm going to look real stupid if this does turn out to be a tragedy lol, but after everything Niibashi has done to support hrkg I really doubt it will. Or at least that would suck for the story imo, and personally - even after skimming through past chapters - I haven't really noticed any flags for a love triangle. Then again I'm not particularly smart so..
A belated thank you for the chapter!!! It was really cute, I love Niibashi a lot and it's nice to learn more about him :')