Appears in the story "The Case of Hidemi and Nanae", which takes place in 1986. Hayashi is another girl who'd hunted mermaids and failed to catch one, turning into an "H" mermaid that Hidemi runs into. Later, she shows up at the school in human form at the same time that another male student disappears and, when Hidemi goes to her house to investigate, finds Nanae guiding Hayashi into a taxi. Hidemi follows them to the seashore, where she finds Nanae chanting the words to the ritual — except this time it results in Hayashi turning into a real mermaid, with a fish bottom half. A horrified Hidemi is witness to Nanae consuming Hayashi's flesh, piecing together many years later that a different piece of mermaid lore indicated that consuming a mermaid's flesh granted an abnormally long life.