Fate leads diving instructor Sha Zi to a magical ring that allows her to transform her appearance, bringing her into the life of Han Hai, a fashion designer haunted by the disappearance of his fiancée, Yu Yu. Believing that Sha Zi’s transformation into Yu Yu could unlock the truth, Han Hai views her as the key to solving the mystery. Over time, their connection deepens, and they open themselves to the possibility of love.

在命运牵引下，潜水教练沙紫捡到一枚戒指，虽找不到主人，却发现其拥有变身的魔力，并意外结识了戒指主人的未婚夫韩海。韩海是著名设计师，因无法忘记失踪五年的爱人于羽而痛苦不堪。他坚守五年之约，誓要揭开真相。起初，韩海认为沙紫的变身是解开谜团的关键，但沙紫的真挚灵魂逐渐温暖了他。经历风雨后，两人感情生根，韩海释怀过往，沙紫也被他的真诚打动，勇敢接受爱情。