Kekkon Aite no Jouken ni Pittari datta no wa Shokuba no Kouhai Joshi deshita.

Still single at age 33, Haruki Shiina is standing at the biggest crossroads of her life. While unlucky in love, she's popular among her female coworkers for her laidback and boyish personality. The only one who gives her the cold shoulder is Risa Takagai, a beautiful and capable new hire who is already climbing her way up the corporate ladder. Haruki sees her as her biggest rival and is sure that the feeling is mutual, but why does Risa always seem to be watching her...?
(Source: Renta!)