Let's Stop Breaking Off Engagements at Graduation Parties ~ I'm Not Bullying My Sister-in-Law

"Adelaide Maroon! A man who would oppress his sister is not worthy of me! I hereby break our engagement, and I shall take this Kate Maroon as my new fiancée!" This is a noble academy in the Kingdom of Ecru, attended by the children of aristocrats. Moreover, it is in the middle of a graduation party. The one who suddenly shouted the breaking of an engagement was Austin Ecru, the second prince of this kingdom. And clinging to his arm was Kate Maroon—Adelaide Maroon's stepsister of the same age. Adelaide, who had her engagement broken off on the grounds of mistreating her stepsister...