Onna Kaijin-san wa Kayoizuma

Rikuto is a righteous corporation that has destroyed the evil organization Asterozoa. Shiraha Shusuke is a corporate slave working in the "Monster Countermeasures Department."

Next door to Shusuke's house lives Nadivra, a female monster and executive of the evil organization --!? "Welcome back, Shu-san!" he says in a sweet voice. Greeting Shusuke like a new bride, Nadivra, blushing as she covers her face with something like a visor, proposes "assimilation," literally becoming one with him!

Furthermore, various monsters begin to approach Shusuke, including Mizuku, a female fox monster, and a female Asterozoa monster who holds a grudge against him!

This is the start of a bizarre romantic comedy featuring a female monster living next door and a corporate slave!

(Source: Shueisha, translated)