Ikumi works diligently at the same company as her overconfident husband, but he pays her no attention and regularly visits hostess clubs under the excuse of entertaining clients. Lonely and outwardly plain and serious, she secretly masturbates during overtime because her mature, voluptuous body can no longer suppress its desires. Company president Ozawa catches her in the act and orders her transferred from clerical work to become his personal secretary—as punishment, she must also become his mistress and share his pleasure.