Help please!

I don’t remember much but I somewhat remember a scene that this guy was living in an apartment and he had a next door neighbor who were 2 girls who seemed nice but in reality they were an alien or something. Kinda looked like a squid or octopus. I don’t know if it’s yaoi or shounen ai or even bl at all. It was colored though. OH also the main guy had a roommate and the roommate was hiding that he was in an organization that eliminates the alien creatures. But I could be wrong on that, it’s been years since I last read it