Chiaki is Fumika's coworker and superior.
Chiaki looks to be around Fumika's age but is actually much older. She doesn't differ much in attire to Fumika besides wearing a thick red and black scarf with white gloves, but differs greatly in hair and eye color. Her hair color being blonde with ruby red eyes. She is shorter than Fumika.
Chiaki has a bright personality and likes to express her emotions outwardly, whether they be related to frustration, or happiness. As observed by Fumika, Chiaki usually is not as diligent about her job as Fumika is, and if a delivery is too much of a pain, she will generally drop it, marking the letter with an invalid addressee.
Chiaki was a human 50 years prior to the start of the stories plot. She grew up and fell in love with a man who lived around the same town she did. The two of them enjoyed many of life's many wonders together. One night, driving home, Chiaki's friend was about to propose to her, but an oncoming car crashed into their vehicle, killing Chiaki in the process. In the end, she realizes that the man she was with died (after having lived a long life) and left her a shigofumi on his grave. She cried because she didn't realize that he never moved on or married because of her death.