Hataraki Man 

This is a set of one-shot stories of working people drawn from the viewpoint of Matsukata Hiroko, who is a 28-year-old single woman and is an editor of Weekly Magazine, JIDAI. She’s often at odds with Tanaka Kunio, a novice editor. Her work already stresses her out and he’s unapologetic about his own mistakes! Everyone refers to Hiroko as a masculine woman for how seriously she takes her work. She smokes too much, works too much, and never has sex. However, when it’s time to get a story done, she switches into “Working Man” mode where her testosterone in her blood increases, she works three times her normal speed, and all thoughts of life’s necessities disappear. (Source: Entropy) Note: Manga is on hiatus since 2009.