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

Haruki Shiina, 33 and still unmarried, faces a major turning point in her life. Though she lacks romantic luck, she is well-liked by her female colleagues for her easygoing, boyish demeanor. Risa Takagai, a new employee known for her beauty and competence, is an exception—she keeps her distance from Haruki. Haruki views Risa as a professional rival and believes the feeling is shared. However, she can't help but notice that Risa often seems to be observing her.