Chiaki is a friend of Fumika and a fellow mail carrier in the Shigofumi franchise. Her Aaron's Rod is named Matoma.
As a human, Chiaki lived in a small town and fell in love with a man named Saizou Kiyosumi. Saizou reciprocated her feelings and was on the verge of asking Chiaki to marry him, however he was unable to due to a tragic car crash that killed her.
Chiaki is a character from both the Shigofumi visual novels and the 2008 J.C. Staff anime series bearing the same name. In the series she is voice acted by Masumi Asano. Chiaki make her first anime appearance in episode 4, "Tears".