Douki-chan is basically stuck in an endless loop of unrequited feelings for her coworker Douki-kun. She's convinced she's in constant competition with every other woman in the office for his attention, and despite repeatedly failing to actually confess how she feels, she keeps trying anyway. It's kind of her thing—fumbling her way through romantic gestures that never quite land.
The weird part about her character is that despite being the whole show's main character, she doesn't even get a real name. "Douki-chan" literally just means "equal," which is actually pretty fitting since she and Douki-kun were hired on the same day. They're coworkers on equal footing, not in some hierarchical senpai-kouhai setup. So the naming mirrors their relationship dynamic right from the start—though obviously Douki-chan sees it as way more complicated than that.
Content compiled by AnimeList.moe from publicly available sources.