365_days_to_the_wedding
A romcom manga by Wakaki Tamiki.
Oohara Takuya and Honjouji Rika work at the traveling agency JTC. One day, there's an announcement that one of the unmarried employees will be transferred to the company's new branch office in Alaska. As they both are unmarried and none of them wants to go, the agree to get falsely engaged to avoid getting transferred. But will things go just as smoothly as they first thought?
An anime adaption aired in 2004.