Responses
The sly eyes, the scheming, the manipulating, the possessiveness--it's a misdirection. But he could have gone either way, plotwise, as I put in a comment yesterday--either he's in love and wildly jealous or he's a sadist and controller. I'm glad he's not a sadist. :D But when you separate someone from the person who makes them feel happy, safe, and at peace, that makes you a "bad guy" in a kind of way.
Apparently I am the only one who doesn't think the neighbor is a bad guy ╮( ̄▽ ̄)╭
I actually believe that he has simply been with Kachou since forever, that he is crazy in love with him and that he is just trying to monopolize him, which makes me feel sad for him to be honest :(
SPOILERS:
Thankfully, he has his own spin-off: https://www.mangaupdates.com/series.html?id=133747
I am doing my happy dance right now ☆*:.。. o(≧▽≦)o .。.:*☆