Usotsuki Heika ga Watashi ni Shuuchaku suru Riyuu

Suzuka, a girl who was transported to another world during her childhood, was chosen to become the "Priestess of Ice." But she never possessed the strength or power everyone had expected. Instead of receiving praise, she became the target of scorn and mistreatment—especially from Adolf, the cold-hearted king of the Ice Kingdom, and those around him. Years pass, and fate brings her face-to-face once more with someone who once saved her—Warren, her very first love. But the reunion isn't what she hoped for. After a fleeting moment of joy, he surprises her with a sudden kiss that stirs her emotions and throws her heart into chaos. As Suzuka struggles to understand the behavior of the boy she once loved—now a man changed by time—she becomes entangled in a complex web of fate involving another priestess named Kako, and King Adolf, who is no longer just a symbol of cruelty, but a key player in her emotional destiny. A powerless priestess x a ruthless king. A forbidden love story where fates intertwine in an unforgiving world, where the heart becomes a weapon—and the past, the key to the truth. (Source: Kadokawa, translated)