Lost Girl wa Koi o Suru

From Day of the River:
Nakajima Hiromi was born into an ordinary family and raised under ordinary circumstances. Working at a medium-sized company, she hopes that one day she'll be able to attain some sort of happiness. With the fear of being isolated, Hiromi isn't sure how to interact with her introverted coworker, Katsuma Yukihiro. But in order to help things along, somehow Hiromi has entered his home... and will be living with him?!