Momoko Amamiya is the landlady of the boarding house that serves as the childhood home of Yukito Yanagi on the Ayaka Islands. She functions as a mother figure to Yukito and to the three disciples of his late father, which include Jingi Sagawa, Haruaki Kurama, and Aka Ibuki. She enjoys cooking and is known for her impressive tolerance for alcohol. At first glance, she appears gentle and quiet, but she is not afraid to give Jingi a piercing look when his antics begin to overwhelm Yukito. She also strongly disapproves of the ongoing conflict between Haruaki and Aka, sharing Jingi's desire for peace among the group. Her motivations center on maintaining a stable and harmonious home for those in her care, and she provides a grounded, nurturing presence throughout the story. While she does not undergo significant personal development in the series, her role as a steady anchor supports the main characters during turbulent events. Her notable ability is her striking capacity to drink large amounts of alcohol without apparent effect, though she possesses no supernatural powers or combat skills and remains a purely supportive figure.