The Villainess Is Adored by the Prince of the Neighbor Kingdom

Lady Tiararose Lapis Clementille is a character from an otome game she played in a past life. However, when she is reincarnated, she doesn't become the heroine but rather the fiancée of the main love interest, Prince Hartknights Lapis-Lazuli Lactomuth, who happens to be her worst enemy. Tiararose is falsely accused of crimes at their graduation ceremony, leading Prince Hartknights to condemn her and disown her, opting to marry the actual heroine, Akari, instead. The villainess is then saved by Aquasteed Marineforest, the prince of a neighboring kingdom, who reveals that he has been harboring feelings for Tiararose and decides to marry her.