Mrs. Reiko, a dedicated female teacher (Rino Ichijo), leads a busy life filled with purpose and responsibility. She shares a strong rapport with her students and takes pride in her work. On weekends, she invites struggling students to her home for private tutoring. As she patiently guides one earnest boy, she finds herself emotionally stirred by his sincerity, drawn into a whirlwind of forbidden feelings. Her husband has been away on a work assignment for nearly a year, and though she's aware of it, her body craves intimacy—her desires as a mature woman becoming impossible to suppress. She crosses the line. But soon, her secret is discovered by one of her students.