A globetrotting businessman named Haruto, a salesman at a general trading company, has perfected a work-hard, party-harder lifestyle. He is openly gay and uses his frequent overseas business trips to build a network of casual sexual partners in each city he visits, carefully avoiding any emotional attachments. On a flight to France for work, he encounters a strikingly handsome man named Albrecht, a wealthy, charming German who manages a luxury hotel chain. Despite being immediately attracted, Haruto instinctively holds back, sensing that Albrecht is too perfect for a mere fling. He gives a vague promise to meet again if fate allows, and they part.

To his surprise, they cross paths again at a high-end restaurant in Paris. Emboldened, Haruto initiates a seduction that leads to an extraordinary night together in a hotel suite. The encounter is so intense and pleasurable that Haruto finds himself unable to forget it, even as he tries to move on. He gives Albrecht a fake phone number and lies about his departure date, determined to return to his carefree routine. But Albrecht, now infatuated, tracks him down the very next day with a bouquet and a straightforward proposal to start a relationship. Haruto refuses, insisting he only wants no-strings arrangements, but Albrecht stubbornly woos him, even accepting Haruto's condition that they begin as casual sex partners.

What follows is a relentless, globe-spanning pursuit. Albrecht uses his wealth and influence to appear in Haruto's business trips, eventually even securing a work partnership with Haruto's company. Haruto finds his carefully maintained resistance crumbling as Albrecht's devotion and charm wear down his defenses. He begins to feel jealousy and possessiveness, emotions he has never allowed before. Just as Haruto starts to open up, Albrecht's stern butler, Raymond, arrives from Europe and deliberately disrupts their growing bond, creating new obstacles.

Rumors surface that Albrecht has an arranged marriage waiting for him back home. Hurt and confused, Haruto confronts his own feelings during a joint business trip, and the two finally confess their love. They agree to spend Haruto's birthday together, but Albrecht is called away to a formal meeting with a potential fiancée. Later, Haruto learns that Albrecht actually orchestrated the entire marriage talk as a strategic move to secure his family's approval and protect their future—he had no intention of marrying anyone else. With the misunderstanding cleared, Albrecht and Haruto solidify their relationship. Raymond eventually accepts the union, and the pair settle into a happy, openly affectionate life together, blending their worlds of business and romance.