Tensei Shita kedo, Ouji (Konyakusha) wa Akirameyou to Omou

The Prime Minister of the Noin Kingdom, Duke Zariel, has a daughter named Christina, known for her silver hair and amethyst-like eyes. She is engaged to Alberto, the First Prince of Noin, a childhood friend. After becoming deeply infatuated with him following their engagement, she acted passionately, but he eventually distanced himself, failing to attend her fifteenth birthday and only sending a gift. Upon seeing the hair ornament, she realizes she is in a world from a dating simulation game she once played, and she is cast as the love rival. At this point in the story, the prince has become involved with the game's main character, Clara. Christina's emotions of jealousy and pride lead to heartbreak, as she experiences a painful, innocent romance with a man who no longer belongs to her.