A young husband from a Japanese confectionery store was killed by someone 15 years ago. According to the man's son, Takatsuki Tsubaki's testimony, the police arrested a female worker and charged her for murder. The female worker's daughter, Nanaoka Nao was Tsubaki's childhood friend as she often visited the confectionery store where her mother worked. The two were each others' first love but had to separate due to the incident.

15 years later, Tsubaki and Nao meet again unexpectedly. Tsubaki did not realized that she was the childhood friend and proposed to her to avoid an arranged marriage. Nao accepts Tsubaki's proposal to prove her mother's innocence. However, the couple starts to get attacked by Tsubaki's mother's harassment and the family circumstances.