G-cup real estate agent Manatsuki Seria is trapped in a room where she cannot leave without receiving an enema. A client threatens to hold her responsible, forcing her to expose her bare anus. Her inexperienced anus is toyed with mercilessly, causing her to writhe in agony. After being made to defecate via enema, she is finally allowed to exit—only to be immediately captured by a perverted doctor and locked inside a room where lewd medical examinations are forced upon her. She reacts nervously to the obscene palpations. Upon waking from anesthesia, she finds herself in M-shaped bondage with her anus forcibly spread open. Powerless to resist, she undergoes compulsory enema treatment under the excuse that feces are "in the way." Gradually implanted with anal fetish tendencies, she experiences the ultimate in humiliating training within a room where hypnotic arousal techniques push her shame to the extreme.