Kana and Nishijima, coworkers at the same office, share a secret affair, stealing moments together amidst their busy work lives. Both married and bound by family responsibilities, freely meeting is nearly impossible—yet they share one mutual desire: to experience pure, uninhibited sex, just once, where they can forget everything else. To fulfill this longing, they've spent the past three months planning what they call a "business trip"—a cover for their illicit getaway. Finally, the day arrives. Meeting at the station, they shed their suits, change into casual clothes, board a limited express train, and head to a quiet inn. The moment they arrive, they passionately lock lips, beginning their precious, intimate time together—just the two of them, alone at last.