When Kaolinite was sent out to collected a Pure Heart Crystal, she releases a Daimon Egg, and it implants itself into a tree.
Later, when Rei ties a paper fortune to the tree, the tree senses her, and mutates and transforms into Mikuji. When Rei attempts to transform, Mikuji knocks her Star Power Stick out of her hand and tackles her to a wall. She then reveals a black star mark on her chest and a beam appears, and starts to painfully extract Rei's Pure Heart Crystal.
Hearing Rei's screams, Usagi transforms into Sailor Moon, but Mikuji throws her with her "hair". She also succeeds in trapping Minako, Ami, and Makoto before they can transform. Tuxedo Mask is able to stop Mikuji for a split second so that Sailor Moon can perform Moon Princess Halation, but the Daimon counters with paper fortunes, and is able to counter both the attack and knock the Cutie Moon Rod out of her hand. Mikuji then pins Sailor Moon up to a tree and bits the Crystal Star, causing the Silver Crystal's light to go out, and Usagi to detransform.
With no one left to attack, Mikuji finishes extracting Rei's Pure Heart Crystal. But the very moment Mikuji takes the Crystal, a orange ball of energy and blue ball of energy suddenly attack and destroy her.
Mikuji could cause various parts of her body to form a hard, stony substance which would detach itself and could pin individuals to trees or walls. The missing segments would simply regenerate almost immediately. She could emit a stream of fortune-telling papers from the palm of her right hand, which were powerful enough to counter Sailor Moon's Moon Princess Halation, and wore a backpack that could fire fortune-telling sticks that would split open and pin her opponents down. She even had a large ponytail shaped like a shrine bell rope that could grab things and squeeze them tight as she swung them around in midair.
- Mikuji is among the Daimons that appear in Sailor Moon: Another Story. Numerous Mikuji could be fought during Sailor Jupiter's story in Chapter Two, inside the Protection Tree beside Medias village in Canada.
- MIkuji was one of the only two Daimons (the other being Daruma) who was not killed by Sailor Moon, as she was destroyed by Sailor Uranus and Sailor Neptune.
- Mikuji was one of two Daimons (the other being U-Baulla) who was created from a living thing - in this case, a tree.