Nao Okura adored helping her mother make wagashi, a revered Japanese delicacy, when she was younger. Her mother landed a job as a wagashi maker, where Nao met Tsubaki Takatsuki—Kogetsuan's heir—filling her childhood with warmth and happiness. But, the good times vanished when tragedy struck, leading Tsubaki to testify against Nao's mother, landing her in prison on false charges.
Many years later, Nao—now Nao Hanaoka—works at a reputable wagashi establishment. But fate leads her back to Kogetsuan, where she encounters Tsubaki as a cruel man, barely recognizing her. In a surprising move, he proposes to Nao, hoping to elevate Kogetsuan's wagashi quality. Despite no romantic feelings towards him, Nao agrees to use the marriage as an opportunity to discover the truth behind what happened to her mother.
Thus, commences their marriage of convenience, which may evolve into something more.