Hotaru no Hikari: It's Only a Little Light in My Life.

Hotaru works for a famous interior design company. It's a glamorous job, but Hotaru's private life is totally the opposite of glamorous. She lives alone, and when she isn't working, she's mostly lazing about her rented house in training wear. She's really not interested in doing anything, much less dating. "I'd rather lay around than fool around," is her motto. One day her landlord's son comes to inspect the rental property, not knowing that someone is living there. He is shocked at the mess, but not as shocked as Hotaru, as he turn's out to be her fastidious boss, Takano.