Suddenly, I've become the (temporary) fiancée of an older, perfect sergeant -. Ayame hides the fact that she is a high school student due to family circumstances and goes on an arranged marriage. There, she meets Kujo, a perfectly good-looking sergeant who is the next president of the company. Ayame is taken with Kujo, and they suddenly find themselves on a date alone...? The gentlemanly and mature Kujo's escort keeps you on the edge of your seat! What will happen to their overly sweet engagement...?