The Prince Is in the Villainess' Way! Series by Minami Shiina

Iris, the "Wise Princess Who Never Smiles," has just remembered her past life as Fiona, Warrior Princess from the neighboring kingdom. In this lifetime, however, the events that lead to Fiona's death have yet to happen, and Iris becomes determined to use the knowledge from her reincarnation to stop the person she suspects is behind her Fiona's cousin, Prince Alvin. In disguise, Iris moves to the neighboring country and becomes the princess' educator... moreIris, the "Wise Princess Who Never Smiles," has just remembered her past life as Fiona, Warrior Princess from the neighboring kingdom. In this lifetime, however, the events that lead to Fiona's death have yet to happen, and Iris becomes determined to use the knowledge from her reincarnation to stop the person she suspects is behind her Fiona's cousin, Prince Alvin. In disguise, Iris moves to the neighboring country and becomes the princess' educator. But when she meets Prince Al, he turns out to be a cool-headed flirt, who, most-shockingly of all, is actually very sweet with Fiona. .. Can Iris figure out the truth in time to save Fiona from her fate? less

Iris, the "Wise Princess Who Never Smiles," had her memories of her reincarnation come back to her. She discovers that Fiona, a princess of a neighboring kingdom, is her from a former life, and that she is in danger due to Prince Alvin's betrayal. Iris goes to the neighboring country as the princess's educator to save Fiona, but an obstacle stands in her way in the form of a cool-headed prince who has no sense of tact... moreIris, the "Wise Princess Who Never Smiles," had her memories of her reincarnation come back to her. She discovers that Fiona, a princess of a neighboring kingdom, is her from a former life, and that she is in danger due to Prince Alvin's betrayal. Iris goes to the neighboring country as the princess's educator to save Fiona, but an obstacle stands in her way in the form of a cool-headed prince who has no sense of tact. So unfolds the love between a wise princess who never smiles and a cool-headed prince. less