Fujimaru is a pale, athletic young woman with voluminous, neck-length brown hair; standing at a height similar to Tonooka. Her locks clump just below the chin, alongside a flyaway strand or two.
In her trion body she wears the standard Operator uniform, leaving her jacket open, top button unfastened, and necktie omitted (which might be due to her large chest). During Yuba Unit's reunion at a restaurant, she sports a cuffed button-down shirt with striped decals down the center.
Yuba Unit's operator exhibits a lively demeanor that is on display when imitating her former teammate's mannerisms prior to Round 8, or in her irked outcry following said member's wistful remark in-person. This casual outlook on life can be seen through her laid-back appearance; although it was this same frankness that had her popularity plummet in school. She also has a tendency to shout exclamations like, 'Ack!' or 'Yeesh!'  While the aforementioned may all point to a vibrant personality, she has the capacity to act as 'mediator,' as well.
Having been a part of Yuba Squad for quite some time, he appears to know how Fujimaru operates, directing his comment about the new Yuba Unit to her specifically.
They attended high school together, and are good friends.
- (To her squadmates) "Look sharp! If we lose our high rank, old Kanda will be like... 'Guess Yuba squad's hopeless without me.' And he'll have that smug look when he says it."
- (In response to Kanda) "There it is! I toldja he'd say some crap like that!"
- "Fujimaru" (藤丸?) means "Wisteria circle" or "perfect Wisteria".
- According to Volume 21, she likes;
- Carbonated beverages
- It is likely that Kako's original hairstyle would eventually become Fujimaru's, as the author noted; "I really like this hairstyle, so I'll save it for someone else."