Sayless is a mute woman met by the protagonist in the parallel world of Dela Grante after his arrival from Earth. Her inability to speak earns her the name "Sayless," bestowed by the protagonist following prolonged, unsuccessful attempts to learn her true name. Residing near a forest, she faces peril from hostile creatures until rescued. After the knight Illia, the protagonist's initial guide in Dela Grante, dies, Sayless becomes his sole companion. Isolation and mutual dependence foster a romantic relationship, culminating in the birth of their daughter, Yu-no. This bond develops partly from resignation, as the surrounding desert traps them in the forest, preventing escape.

Sayless displays kindness and resilience, maintaining warmth despite her muteness. She forms a profound connection with the protagonist and embraces motherhood, showing deep devotion to their family. Her character serves a critical narrative purpose: facilitating Yu-no's birth and early story. Yu-no ages rapidly due to supernatural factors, becoming central to Dela Grante's larger conflict.

Imperial guards eventually locate Sayless. They administer a humiliating virginity test, declaring her "defiled" due to motherhood. To prevent the protagonist's certain death during the ensuing confrontation, Sayless commits suicide. The anime depicts her slitting her throat, while the original visual novel presents an alternate version where she bites off her tongue.

Her death profoundly impacts the story, triggering the protagonist's subsequent imprisonment and quest to rescue Yu-no. Across media adaptations, her portrayal remains consistent as Yu-no's mother and her ultimate self-sacrifice.