Aiko Maebara

As the devoted mother of Keiichi Maebara, this character plays a subtle yet significant role within the series' complex narrative. Alongside her husband, Ichirō, she is introduced during the Onikakushi-hen arc. Although her physical presence is limited during the initial two anime seasons, she emerges more frequently throughout the various manga adaptations, providing essential familial connections to the protagonist's unfolding story.