Yutaro and Beth, an international student, are sophomores in the same high school, although they are in different classes. Their high school life is in jeopardy. Yutaro has to move to Kumamoto due to his father's job transfer, and Beth's parents, who are in the midst of a divorce, are racing to bring their daughter back to the United States. Not wanting to change schools by any means, the two come up with the idea of a camouflage marriage.

The "marriage" of Yutaro and Beth caused quite a stir. Yutaro's grandparents, Takeyoshi and Toyo, were very much against the marriage. On the other hand, Ken, who loves Beth, and Yayoi, who is crazy about Yutaro, are determined to get their lovers back, no matter what it takes. They begin to interfere in their lives.