Kanaka

The artificial intelligence staff that Fumika carries is named Kanaka in the anime and Mayama in the light novels, and are drastically different between the two media. The function of the staff is meant to aid the shigofumi mail carrier by keeping track of senders, receivers, the delivery area, and supplementing other usual tasks. The mail carrier can give the staff a numeral code pertaining to a program which can be activated and aid the mail carrier further, such as turning them invisible, or supplementing white wings on their back to enable them to fly, though there are time limits on these programs. The staffs carry their own personalities and have the ability to levitate. In the anime, Fumika's staff Kanaka has a female voice and a loud, boisterous personality which directly contrasts Fumika's otherwise placid disposition. Kanaka often gives Fumika her opinion on matters pertaining to who she is delivering letter to, though Fumika just goes along her business as usual either way. Despite technically not being alive, Kanaka still insists that "she" be referred to as a person, or in terms of what a person would do, such as while levitating or regenerating which she calls "standing" and "sleeping" respectively. Kanaka is prone to making mistakes while on the job, such as misplacing letters.

In the light novels, Mayama as the staff is called, has a young boy's voice, though still serves the same function of supporting Fumika in her delivering. "He" always talks down to Fumika and proves her to be wrong in certain situations. He has never been able to beat Fumika at shogi, though he can still do things she cannot, such as reading foreign languages.