|Location||Pitch Black World|
|Height||135 cm (4' 4")|
|Affiliation||Pitch Black World|
Kiku is a red-skinned oni wearing a beige sweater over a white dress shirt with a blue bow tied to her collar. She also wears a dark grey skirt, baggy white socks and dark red loafers. Her hair is white and tied in two long braids, each ending with blue ribbons.
She wields a pitch-black kanabō (spiked iron club) with a bandaged hilt and a grip handle at the end; it possesses two asymmetrical eyes with red irises, a long diagonal mouth full of razor sharp fangs and a long tongue.
In some artworks, she is seen wearing an orange kimono with a dark red nagajuban and obi.
It's been said she has a pure personality, alongside that she is very powerful. However, it's hard to tell what she's thinking about, and that she's a bit of a difficult type. 
Not much is known about her background.
Up to this point, Kiku has only appeared in some of Deep-Sea Prisoner's illustrations.
Kiheki is Kiku's sister. She is close to Kiku, but despises Glasses, Kiku's boyfriend, calling him a "troublesome lover".
Kiki is Kiku's brother. They seem to be close.
Glasses is Kiku's boyfriend. She sometimes goes to his house to cook breakfast for him. In one comic, she let Glasses warm his hands in her sleeves.
- Kiku's kanabō (spiked iron club) hates Glasses for some reason.
- Kiku's genderbent version has long sharp nails similar to the common portrayal of red oni, unlike his female counterpart (though it's possible she has them and they're just hidden by her sleeves).
- Kiku tends to wear loose socks; with her genderbent version, Kiku's shirt is left untucked which are both violations of common school dress codes and are related to delinquency. Kiku's loose socks and short skirt are also both commonly associated with Kogal fashion.
- Kiku's name means "red oni."
- Funamusea has stated that she will eventually make an appearance in Obsolete Dream.
- " It’ll be done soon, so just wait a bit." (To Glasses, while preparing food)
- "Is it warm?" (To Glasses in a Mini-Comic)