Watashitachi ni wa Furerarenai Jijou ga Aru

Sakurako is rather plain, doesn't think very highly of herself, and since she began working at her current job, she's secretly been in love with her section chief, Agatsuma. Agatsuma is good at his job, kind, and everyone loves him. Sakurako is a late bloomer and she never could quite muster up the courage to tell Agatsuma how she feels, so she settles for watching him from afar. Soon, it is all too late for her when Agatsuma is transferred to the company headquarters and out of her life. (Source: MangaPlaza)