Satie is a human who endured enslavement under the designation Thirteen. Ike discovered her concealed beneath an office table after conquering her town. This encounter allowed her to see Ike's real face, exposing his hidden humanity. Rather than execute her, Ike spared Satie's life and specifically appointed her as his personal maid, reasoning her human nature made poisoning attempts unlikely. Upon learning her birth name—Satie, given by her mother—he ceased using her slave number.

Satie developed romantic feelings for Ike, emotions she initially struggled to comprehend. This affection created a rivalry dynamic, with Lilith, a succubus also enamored with Ike, viewing Satie as a competitor for his attention. As part of her duties, Satie sometimes accompanied Ike on undercover missions within human territories when he operated without his disguise. These excursions took on the quality of unofficial dates during their tasks. Her position entangled her in complex dynamics involving both demons jealous of Ike's success and humans hostile to his coexistence efforts.