The sole female technician at the repair company, Koiro Yuuki, heads to a client's mansion alongside her coworkers Iida and Shigeya, as well as their boss, Takimoto. The day's task is plumbing repairs under the scorching summer heat. While the men handle outdoor piping, Yuuki and Takimoto work on the second floor where the air conditioning is running. The male staff harbor growing resentment toward Takimoto's arrogant attitude. As time passes, the upstairs toilet repair progresses smoothly. Just as Yuuki prepares to report completion to her superior, Takimoto suddenly unzips his pants and demands she take his cock in her mouth. The atmosphere instantly shifts, plunging into a tense and oppressive situation.