Toshiue Onzoushi wa Kon'yakusha (Kari) o Ijiwaru ni Dekiai Shitai

"Suddenly, I've become the (temporary) fiancée of an older, perfect noble's son."

Ayame hides the fact that she is a high school student due to family circumstances and goes on a marriage interview. There, she meets Kujou, a perfect and handsome son of a noble, and the next president of his company. Kujou takes a liking to Ayame, and they suddenly find themselves on a date alone!

(Source: Starts Shuppan, translated)