Strange suicides have been taking place in New York. One day, four girls from the same high school wake up in the morning feeling tired and dizzy and not being able to remember anything about the previous night. In school, they find out that one of their classmates has committed suicide. School is canceled for the rest of the day, but instead of going home, the girls are drawn to a park by butterflies only they can see. Suddenly a man and a woman approach the girls, telling them that they all died the previous night.
Mushishi
They are neither plants nor animals. They differ from other forms of life such as the micro-organisms and the fungi. Instead they resemble the primeval body of life and are generally known as "Mushi". Their existence and appearance are unknown to many and only a limited number of humans are aware of them. Ginko is a "Mushi-shi" who travels around to investigate and find out more about the "Mushi". In the process, he also lends a helping hand to people who face problems with supernatural occurances which may be related to the "Mushi".