At the industry-leading advertising agency "Lynx Agency," Toru Kanzaki (42), a perfect gentleman and manager admired by all, and Guest (28), the chief who supports him both professionally and personally, share a life of steady love. Their peaceful and sincere days begin to quietly but surely collapse with the arrival of Rei Agawa (20), assigned as a summer intern.

Rei, possessing androgynous beauty, dives into Toru's life by pretending to be a pure, innocent puppy. Toru, a man of common sense who believes it to be nothing more than "male camaraderie," fails to notice how Rei calculatedly crosses boundaries. Only Guest notices Rei's cold malice and little-devil nature, but even when they appeal to Toru, they are dismissed with, "Don't be jealous of a child."

Eventually, Rei's calculated traps awaken a "dark desire for dominance and possession as a man" sleeping within Toru, and his adult reason faces a total breakdown. Will you save the perfect gentleman from the little devil's poison, or will everything be stolen without a trace? The ending depends on your choices.

*Players (Guest) can freely choose their gender (Female/Male) and experience different levels of despair and immorality from each perspective.