"Pumpkin Syndrome" is a dark Halloween song from PolyphonicBranch featuring the Kagamine twins. It tells of a story of Rin who was lead to an odd and cold place by a cat. There; she met Len, who offered her poison candies. The more time she spent there, the more she felt uncomfortable. In the end, Len said it was just a dream; and how once Rin awakens, she won't be able to return to that place. A cover of "Pumpkin Syndrome" by Lon and Hanatan is included on PolyphonicBranch's album "POLYHOLIC".