After failing his college entrance exams, Atsushi became a socially isolated NEET. Concerned for his son's situation, his father asked Haruka—his colleague's wife—to become a private tutor. Although Haruka had prior experience as a tutor, she struggled to reach the unmotivated Atsushi. Desperate to boost his concentration, she devised an unconventional teaching method: an extremely bold and hands-on approach using her hands and mouth. This intense instruction quickly escalated, leading to unexpected and explicit developments.