Yumiko had a secret that she absolutely had to keep hidden. A physical relationship with a student. For Yumiko, it was a time so stimulating that she would risk ending her teaching career just to indulge in it. But recently, her student had started demanding a relationship even within the school grounds, seeking further stimulation. It's too dangerous. That's what her reason was telling her. But Yumiko's escalating desires couldn't suppress the impulse to seek thrills…