An enigmatic little girl introduced in season two, episode 4 and then starts to reappear in season two. Little is known about her except the fact she is not an ordinary human as she can wander freely between the mortal plane and Ai's house in the sunset world, sometimes interfering with her and her companions' job. Her appearance is often accompanied by a lullaby-like background music. In stark contrast to Ai, Kikuri has completely blue/purple eyes (including most of the sclera) and her personality is far more childish (yet much livelier as she has the tendency to pull pranks) than Ai's. She has stated that she likes Ai, but her actions and use of powers seem to serve causing the greatest amount of suffering and fear possible. It is as yet unknown whether this is due to true malice or not. Occasionally, she seems to take delight in acts of low-level destruction, such as chopping off flowers or destroying anything that Ai cares for. She has shown incredible skills with her loincloth, using to catch or hit objects. Despite the fact she appears to wreak havoc on her, she takes orders from Ai and Ai alone (in one episode, she shows this while going to touch Ai's grandmother's spinning wheels despite the woman's protests).

In the last episode of the second season, it is revealed that Kikuri is in fact a host for the will of the Spider, which can take over her body as it pleases. As such, it becomes questionable how many of her malicious acts were of her own will and which were instigated by her master. After Ai's death and the release of her beloved ones, Kikuri, riding on the boat, says, "It's over...that was Ai's answer...Well done." As she says those words, she pokes a cherry the color of Ai's eyes in her former childish way.