Missing the last train with her admired senior, she finds herself alone in a hotel room. Forced into a relationship, she tells herself, "They're both girls anyway," yet indulges in extramarital lesbian sex. (Sato Eru, Ouka Rin, BBAN-600)

[Eru Sato's Lace Unveiled] Eru and her admired senior, Rin, start working at the same company. Overjoyed, they get drunk at their first company dinner. Missing the last train, Eru, at Rin's suggestion, decides to share a hotel room until morning... However, the confined space gradually erodes their boundaries and rationality... Her senior reveals a side she's never known before. "I never expected my senior to..." As his alluring expression draws closer, Eru can't resist the unprecedented pleasure, spending the entire night gradually being drawn into the world of lesbianism...