Kagetsumugi is first seen at the entrance of the Puppeteer's Tower introducing herself to Luka, Luka asks her for Magical Thread but she says that only Puppeteers can use that item but she offers it anyway for the desperate Hero before Alice/Ilias drags Luka out of the tower. After Luka and party leaves and starts discussing what they should do next, the focus shifts back inside to Kagetsumugi who is speaking with someone. After an ominous exchange, it’s revealed she is working with Black Alice. She’s creating an army of powerful puppets for the Black Alice faction so they can assume dominance in the war for the Monster Lord’s Throne.
Kagetsumugi is actually the fourth puppeteer. The first was chosen by Black Alice 500 years ago and they’ve been perfecting their technique since then.
She is an extremely powerful puppeteer, armed with four Monster Lords in her doll collection. Goddess Ilias, despite not having seen her creations, once stated that Kagetsumugi would very easily overpower La Croix.
She is last seen talking to La Croix about Black Alice in the Devastated Plains, and is asked why she supports the destructive Eighth when she herself is a creator. Kagetsumugi gives a non-answer before La Croix and her Cirque engage Luka in a fight.
She plays a notable role in "The Night Country and the Heroes of the Seven Worlds", as she mass produced Mukuro dolls for the Alliance of the Queen of Dreams. She then unleashes a "defective" model on Kazuya's party.
Once the heroes have beaten the doll, they ask Kagetsumugi if she will be their next opponent. The small puppeteer answers them that she will take her leave as she delivered the dolls to the Alliance just like she was asked, she claims to want an army of Mukuro Dolls for Black Alice, but tells that she changed her mind after dealing with this free-willed failure before she Kazuya recruit Mukuro for the sake of the doll's happiness. As she leaves to prepare the party for Black Alice, Kazuya asks her if she's a puppeteer or a puppet, upon which she answers that she is "not a puppet" while displaying her monstrous nature before disappearing, shocking Hakunen while Kazuya was already suspicious that she wasn't human at all.