Five years after her husband passed away, Mari is a widowed female teacher who has an overwhelming sexual appetite. Despite being a teacher, she masturbates six days a week to keep her sanity. One day, in order to prevent three of her poor classmates from having to repeat the year, she decides to hold a three-day study camp at her house. While studying diligently, the students are curious about Mari, some of whom peek into her bath, some steal her underwear, etc. Mari is finally able to catch a man's gaze after a long time, and even though she knows it's wrong, her frustrated body is set ablaze...