Beneath her skirt, trapped between her fleshy thighs, lies her deepest secret. The perfect, cold “Hirabara Itsuki” sits under the desk, spreading her knees to shamelessly expose herself to the cowardly teacher “Ōsumi Hino,” who teaches his class from the podium… Her purity was stolen in an experience full of firsts. Taking advantage of Hino’s attempt to escape the relationship, Itsuki blackmails him with the possibility of his parents finding out, becoming a meddling wife and forcing the continuation of their connection. After school, she sneaks into his room, playing with his erection with her feet out of boredom, teasing him, riding him on the couch, and skillfully moving her hips—the perfect cold girl, Itsuki. A clandestine relationship drenched in desire. In public, Itsuki scorns him with cruel insults, appearing cold and distant, but in her room, she meekly awaits his return with a tender expression. And when he comes home, she throws herself into his arms, stripping off her clothes, clinging passionately, seducing him sweetly, and showing him her most affectionate and shameless side. Hino worries about this dreamlike relationship with Itsuki, who has grown into a lascivious and shameless girl… However, something alien to them is about to intrude on their bond.