Plum, a dedicated mushroom researcher, enters the orbit of Hotaru Yuyami and the enigmatic Kinokoinu. Her mycology expertise drives her to analyze Kinokoinu's unique biology as a mushroom-dog hybrid. Through direct interaction with Hotaru, Plum provides scientific insights into Kinokoinu's behavior and characteristics. She meticulously observes and documents Kinokoinu's interactions within its environment and with human companions. Plum's research contributes key understanding, such as interpreting Kinokoinu's motivations behind burning Hanako's belongings to aid Hotaru's emotional processing. Her findings form a core part of the narrative exploring human-supernatural coexistence. Plum maintains a professional yet personally engaged approach while studying Kinokoinu's impact on Hotaru's life.