Heart pounding from morning to night, lovey-dovey at home and at work!

I joined the same company as my brother's best friend, who is also my creepy landlord. Just living together makes my heart tremble, but this guy... Why is he being nice to me? Scary... The story of Oh Sojeong, a young girl, and Cha Gangwoo, a man who falls in love with his friend's younger sister, while living together.