Sachi Moribe serves Momiji Himehagi as a dedicated maid, identifiable by her red hair, purple eyes, and red maid uniform. Her intense devotion manifests in public displays like singing chants about Momiji in parks. Witnessing these moments triggers extreme embarrassment in Sachi, provoking immediate aggressive reactions. She attacks observers on sight, frequently targeting Kazuhito Harumi.

In combat, Sachi wields a modified broom concealing a long blade resembling a naginata. This weapon demonstrates sufficient durability to clash directly with Kirihime Natsuno's specialized scissors, Hasajiro. Repeated confrontations arise between Sachi and Kirihime, often due to Sachi targeting Kazuhito or Kirihime intervening to protect him. These battles typically end without resolution, interrupted by external factors.

Sachi's relationship with Momiji Himehagi defines her core motivation. Her actions consistently focus on serving Momiji's interests and eliminating perceived threats or embarrassments, especially those stemming from her own unguarded moments of devotion.