Konyaku Haki wo Manugareta Koushaku Reijou wa, Otto no Ai wo Shinjirarenai

"I always believed I was the only one who should stand by his side..." Prince Ashley, the first prince of the Kingdom of Sforzia, and Lady Violetta, a duke's daughter, are engaged to be married. Although their engagement was arranged for political reasons, Violetta has worked hard to support him as the crown prince since they were young. However, as she became busier, they started spending less time together, and Ashley became close to a cheerful and naive young lady, who is Violetta's complete opposite. Then, Violetta hears a shocking rumor: "Poor Lady Violetta. Imagine being cast aside by the crown prince!" Rather than let another young woman take him away, Violetta makes a firm decision: 'Fine, I'll be the one to end this engagement!'

https://www.cmoa.jp/title/278550/

https://mechacomic.jp/books/181228