Devastated at the death of her four-year-old daughter, a grieving middle school teacher is horrified to discover that her students aren't as innocent as she thinks.
When Kanako, a model daughter and a brilliant student, disappears, her mother asks her ex-husband, a violent former policeman, to find her. As his investigation progresses, his idealized image of Kanako cracks: the girl hides a dark life that her father can not even imagine.
Ryo personifies water, since whenever something important happens in her life, it rains. She inherits a bathhouse and meets a pyromaniac named Yusaku. Their confrontation leads to an inevitable union, just like elements of nature blend together.
