Kekkon e no Michi

In the Kekkon e no Michi series (結婚への道シリーズ), also called the "On the Way to a Wedding" series:

1) Irekawatta Hanayome (入れ替わった花嫁; A Bride in Waiting):
THE SUBSTITUTE BRIDE
Dr. Lucas Daniels viewed his bride-to-be's temporary disappearance with exasperation, fondness and resignation. After all, she felt the same way about him! Then a beautiful stranger strolled into town, looking exactly like his fiancee. In order to avoid upsetting their families, Lucas asked Sara Martin to stand in as the missing bride. But now he was wondering which bride to marry....

Sara had been searching for ...