Omocha-tachi no Yume

Yume-san is a hot script writer with laid-back demeanor and a chain smoking habit. The heroine is just a high school girl. Don't let the 10 year age difference bothers you. Yuki matures as the story goes by.

After their parents died when Yuki was just 4, Yuki's brother took a job at a gay bar to support her. When he fell in love (with a woman), Yuki wants to be independent as soon as possible so that her brother can have a real family of his own. She approached Yume-san, her brother's acquaintance, and ask him to hire her as his assistant.