Character Arc
Kayo is a key figure in the Bakeneko arc, the storyline that closes Mononoke and revisits the case that introduced the Medicine Seller in Ayakashi: Japanese Classic Horror. A servant within a household preparing for a wedding, she is positioned close to the family's daily life and becomes one of the people who first senses that something is deeply wrong as a vengeful cat-spirit, a bakeneko, begins to make itself known.
Her perspective helps ground the arc's mystery. As the Medicine Seller investigates, the household's polished surface gives way to a concealed wrong, and Kayo's observations and loyalties become part of how the Truth and Reason behind the haunting are drawn out. The supernatural menace is handled with mood and suggestion, keeping attention on the human guilt and sorrow that summoned the spirit.
Within the anthology, the Bakeneko arc carries special weight because it links Mononoke back to its origin, and Kayo is among the characters who give that story its human texture. Her role illustrates how the series uses ordinary members of a household to reveal a hidden past. Casting and arc details for this character should be verified against primary sources.