One and a half years have passed since Kaori's long-awaited married life began, and she has been living each day happily. However, she still feels a certain emotional distance from Tatuya, her husband's stepson. Then one day, her husband announces a week-long business trip. Left alone at home with Tatuya, Kaori feels a bit uneasy—but that uneasiness soon manifests in ways she never expected.