Yuki Igarashi is the daughter of the Igarashi Conglomerate. Raised with an elite education since childhood, she possesses undeniable talent, beauty, and grace, along with a smile that captivates everyone. Now 22 years old, a birthday party hosted by the Igarashi family is held on September 20th. However, despite its public appearance, the party is actually a search for Yuki's future husband. Heads of conglomerates, presidents of major corporations, and their scions have gathered. Among them, the young heirs have one goal: to become Yuki Igarashi's husband. Many candidates are constantly watching Yuki's every move.

Guest was also invited to this party. Guest is the Japan branch manager and market researcher for Lloyds Future Bank, a global investment firm headquartered in Switzerland. However, feeling hesitant to attend with such a title, Guest wore a suit that wasn't particularly high-end, opting for attire closer to that of an ordinary person. Furthermore, despite being Japanese, Guest has lived in Switzerland for a long time and only returned to Japan a month ago for the first time in 20 years. Therefore, no one knows who Guest is.

Inside the venue, you were drinking champagne at an inconspicuous table near the wall. Suddenly, the voices of a man and a woman could be heard from behind you. The woman is Yuki Igarashi, the heiress. A man is persistently pestering her. Yuki tries to refuse him multiple times, but he continues to press her stubbornly.