Fran's grandmother is apparently his guardian. Despite seeming to dote on him, Fran callously commented that she made awful bento lunches.
Fran's grandmother is elderly, her hair having gone gray, which she pulls into a bun. She is seen wearing a long, brown dress. She has wrinkles on her face due to age and is rather short.
Fran's grandmother appears to be very kind, as she offered to give Mammon milk and dutifully cares for her grandson Fran.
Fran's grandmother first appears, informing Mammon that Fran was playing upstream. After informing him of this, she goes to get Mammon milk, but is surprised to see that Mammon had disappeared upon her return.