Mihiro Usami works as a maid in a wealthy household, known for her serious and responsible nature. However, one day she can no longer endure sexual harassment from one of her master's important business associates and finally pushes the man away in defiance. Enraged by her actions, her master decides to punish her under the guise of "discipline." What exactly does this so-called "education" entail? The moment that will drastically alter Mihiro's fate draws near.