Sudai Takashi is an employee of a candy company. After three years, he is promoted together with his new co-worker Kobayashi Chikako. Kobayashi is a person who is not sociable and is dull and shy. She also hides her chest since that caused her some problems in the past. Sudai will try to change this negative girl, and maybe he will start to harbor some feelings for her along the way. (Source: MU)

Kobayashi-san wa Jimi dakedo. is based on a manga published to the author's Twitter account on October 5, 2017. It was originally published on Nico Nico Seiga under the title "Jimi Joshi x Osekkai Danshi" (地味女子×おせっかい男子) before moving to Manga UP! on January 24, 2019.