Machi first appears as a supremely talented ballet dancer, her brilliance eclipsing her friend Ai. This perceived genius hides a secret: her dependence on Aguu, palm-sized entities that grant extraordinary abilities. This reliance on supernatural aid defines her central conflict.

Ai's discovery of the Aguu triggers Machi's transformation into a "Seamstress," a creator and distributor of these talent-bestowing entities. This role pits her against the "Saviors," a group dedicated to opposing the Seamstresses across generations.

Becoming a Seamstress severs Machi's relationship with Ai and embroils her in the larger, ongoing conflict between the factions. Her actions within this role contribute to her eventual mysterious disappearance, a concealed scandal among society's elite.

Her background involves intense pressure to maintain a facade of perfection through the Aguu. The toll of this dependence and her subsequent existence as a Seamstress embody the burdens of artificially sustained talent and themes of envy.