The month is February, but it hasn't snowed all winter. Kanon's father is often away on business trips and might be getting a little too friendly with his pretty young female subordinate; which Kanon doesn't approve of so soon after her mother's death. Her little brother collects insects, but they're dying off

It turns out that these deaths are the first of many a plague to come down. First it's the insects, inexplicably dropping dead everywhere. Then it's the rats, looking for a new food source. And things just keep getting worse...