Arashiyama Kazuomi, who leads an ordinary college life, is actually a sergeant at a top Japanese company. He spends his days drinking with friends from the same seminar and attending blind dates, but he is forced into a political marriage with his childhood friend Hoshuhana Senju, who is also a top company and a rival of the Arashiyama family, and who is extremely handsome.

Kazuomi, who is not very fond of Senju but is willing to do it just for the sake of his family, lives with Senju as a “temporary fiancee” until his brother, the heir to the company and opposed to the marriage, can persuade the family to agree to it.

One day, however, Kazuomi is drugged with an aphrodisiac by a girl at a drinking party, and when Senju comes to pick him up, he declares that they are engaged. Kazuomi thought it was just a way to save him, but Senju passionately confessed that he wanted to make Kazuomi his true fiancee, and kissed him so sweetly that his back was shattered...?