Fumika appears to be around the ages of 14 or 15, though her real age is never mentioned. Fumika has white hair that goes down to around her chest when up, and wears the standard delivery outfit for Shigofumi deliverers. This includes, a navy blue pleaded skirt, chef jacket, and hat. Her navy socks go a little bit above her knees. She has navy colored shoes and a light red cape.
Fumika is almost always calm and speaks in a low monotonic voice. She is serious about her job and carries out her duties even if it takes her longer to deliver a given letter, such as her having to follow the recipient by train to another part of Japan. She does not like normal people interfering with her work, and often has to resort to violence or threaten others with a large gun she carries in order to complete her deliveries. Due to her unusual occupation and the uniform she wears, she is generally not taken seriously when she tells others that she is delivering an "after death letter" to them, but continues to persist until she has handed over the letter. The only time she shows any expression is when around cats which make her very agitated to the point of her losing her composure entirely.
Fumika was raised her whole life by her father, Kirameki Mikawa. Her mother had abandoned the two of them right after her birth which, as a result, caused Kirameki to take out most of his sadness and anger about the situation out on Fumika. He would write on her skin, causing her to bleed immensely. To deal with the stress of her fathers constant "art projects", Fumika split herself into two personalities, Fumi, the side she had all her life, and Mika, the mail carrier and the persona she created so that she wouldn't be alone. Mika soon became Fumika's source for guidance in her life.
- While still the main focus in the light novels, her character is somewhat different. She still appears the same and generally carries the same personality, though Fumika in the novel, for one, hates all insects vehemently and will not even go near them.
- She loves to play shogi (Japanese chess), though she plays on only intuition alone.