Tensei Ningyo Hime wa Awa ni Natte Kietakunai

One day, an ordinary college girl finds herself reincarnated into the world of "The Little Mermaid," a fairy tale she read in her previous life. She didn't particularly like the prince (because she didn't know him at all). But! In order to survive and not fade away into a pile of foam, she is going to do everything in her power to win the prince's heart! I don't want to die!

(Source: Manba, translated)