In the not-so-distant future, humanity faces extinction, not from war or disease, but from a total lack of action between the sheets. With AI doing everything (including flirting), people have stopped dating, marrying, or even having sex. Enter the Onnuri Sex Culture Laboratory, humanity’s last, horny hope. Their solution? A time machine. Their mission? Study the golden ages of getting it on. Meet Garam, an awkward grad student turned chronosexual researcher, who’s now zipping through history under the wing of the mysterious and seductive Professor Eun Ahyeon. From ancient orgies to disco-era hookups, Garam must document sex culture and harvest the elusive energy source known as… Orgasium. History class has never been this NSFW.