Keep Your Voice Down or He'll Hear You -the Guy Next Door Is Mean and Rough-

As Kasumi leaves her boyfriend's house one night, his neighbor pops out to let her know that he can hear them through the walls. Mortified, she swears to never be so loud again... The very next day, she finds out that same neighbor has started working at her job. Given that inter-office dating is prohibited, Kasumi has to make sure he keeps his mouth shut about her and her boyfriend, the section chief. Sometimes, this new guy is rude, but then sometimes he is very helpful... Kasumi is confused. But, oh no! She must keep her voice down... which can be hard to do when he makes her feel better than her boyfriend ever has...!

from Renta!