Two People Who Never Pass Each Other

Audel Mejerda, the eldest son of a duke's family, and Lena Doldogne, the daughter of a marquis family, are engaged to each other. In this country, once an engagement ceremony is held, they are not permitted to break up. The two are scheduled to have their engagement ceremony after graduating from the academy. However, a young lady who approaches Audel appears...? *The second candidate for the title was "Engagement Dissolution Death Match by Infidelity Point System." It's content along those lines. Since I wrote it in a few hours, I might rewrite it.