一流企業に入社した千晴は多忙で彼からのプロポーズの返答は保留状態。誕生日を機に指輪を渡して再プロポーズする予定の彼だったが…千晴は一緒に残業し好意を寄せていた同僚・小田切と会社で一線を越えてしまう。感度が高すぎる千晴は深く刺さるチンポに何度も激しく絶頂し、快感に彼氏を忘れてオフィスでフェラ、ホテルでイキまくり浮気SEX…電話に出ない彼女に不安が募る…心臓を引き裂く胸糞寝取られ！

Chiharu, who joined a top company, is so busy that she hasn't given her boyfriend an answer to his marriage proposal yet. He plans to give her a ring and propose again on her birthday, but… Chiharu crosses the line at the office with her colleague Odagiri, with whom she has feelings for, while working overtime together. Chiharu, who is extremely sensitive, climaxes intensely many times from the deep penetration of his penis, forgetting her boyfriend in pleasure and cheating on him with oral sex at the office and multiple orgasms at a hotel… Her anxiety grows as she doesn't answer his calls… A heartbreaking, sickening betrayal!