Ishigami, who works at a major advertising agency, is dating Ruisa, a receptionist at the same company. However, Ishigami is crazy about Ruisa and is frustrated every day because she won't let him have sex with her raw, even though they are engaged. One day, his boss and a senior at work invite Ruisa to check out a company trip... This is a crossover between a perverted NTR fetish that is awakened in a hot spring inn and repeated intense gangbangs in a semen-stained, milky bathtub. #YoroP