Ket's mother is a minor character who appears in a single scene set in her family's home. She is the parent of a young boy named Ket and the sister of Maki, who is an early customer of Kiki's delivery service. Her physical appearance includes ginger hair and brown eyes, and she is typically seen wearing a blue dress with a white apron.

In terms of personality, Ket's mother is portrayed as a patient but firm parent. Her primary action in the story is to manage her son's behavior. When Ket becomes absorbed in watching television while his birthday party guests are about to arrive, she repeatedly instructs him to turn off the set. Her dialogue in this scene consists of calm and direct requests, such as asking him to turn off the television because his guests will be there soon.

Her motivation within the story is centered on the everyday domestic task of preparing for her son's birthday celebration. She is responsible for ensuring the household runs smoothly and that social events proceed as planned. Her role is to provide a realistic backdrop of family life for the film's main character, Kiki, who witnesses this ordinary mother-child interaction during a delivery. The scene serves to highlight a typical childhood reluctance to stop a preferred activity, a moment of small-scale conflict that resolves without major incident.

Regarding her key relationships, the primary one is with her son, Ket. She is also connected to her husband, Ket's father, who appears in the same scene, and to her sister, Maki, who originally sent the birthday gift. The family also owns a pet named Jeff. This character does not undergo any development, as she appears only briefly and serves a purely functional role in a single sequence. No notable abilities are ascribed to her.