Ah Nian, a young girl from the Ji tribe, encounters Xiao Zisu, a boy from a different tribe, in her hometown of Sushui. They eventually fall in love and as their wedding day approaches, Ah Nian eagerly waits for her lover’s appearance. Instead, she is met with disaster—the destruction of her tribe brought by Zisu’s older brother. This massacre causes the two to lose all memory of each other. Seeking revenge for her people, Ah Nian adopts the alias 'Xiao Man' and infiltrates the General’s manor, pretending to stay by Zisu’s side. The memoryless Xiao Zisu is both suspicious of Xiao Man’s sudden arrival and intrigued by a sense of familiarity, believing she holds the key to regaining his lost memories. As time passes, Xiao Man begins to realize that Zisu is not as cold-hearted as she initially thought. His warmth and barely hidden affection lead her to suspect that someone else might be responsible for the massacre. Through fragmented memories, the two gradually recover their past and work together to fulfill the forgotten promise they once made.