The Walkley Ducal House, one of the noble families comprising the Elliot Kingdom. Its heir apparent—Alphons von Walkley—is physically frail due to his innate constitution and unable to attend the academy properly.

One day, Alphons, feeling well, attended the academy for the first time in about two days, enjoying his student life.

Then, at lunchtime. As he, his younger sister, and her friend were about to eat in the academy's dining hall, the First Prince of the Elliot Kingdom and his companions arrived. Startling words were announced to Alphons and the others, who were surprised by the sudden event.

Namely, that the engagement with his younger sister would be broken off…