Newly hired teacher Nagi Saizumi is framed for losing exam papers and forced into becoming a human model for a "compliant naked class" during physical education. Falling into the manipulative hands of Narusawa, her strong sense of responsibility is exploited as shame and temptation intertwine, gradually transforming her into an insatiable, depraved instructor. Under the guise of experiential learning—where direct physical contact with the female body is permitted—Nagi discovers her own limits and begins treading a new path. Amid this twisted scenario where duty clashes with desire, her mind slowly unravels until she ultimately succumbs completely to madness.