Asako Mizusawa (Hitomi Kuroki)suffers from her mother-in-law's abuse. Finally, her mother-in-law diesand Asako is relieved of her nightmare like existence. Two years later,her only son Yuta (Tomohiro Kaku) wants to marry Ririka (Saki Aibu). Asako and her husband Hiroyuki (Junichi Ishida)oppose their marriage. As a condition for their acceptance, Asako asks to live with them. Asako thinks Ririka will say no and give up marrying her son, but Ririka accepts the condition. Yuta and Ririka finally marry.
On the day Yuta and Ririka come back from their honeymoon, Asako doesn't know how to deal with them. Her husband Hiroyuki has yet to comehome. Asako and Ririka begin to drink and they talk about Asako's deceaesd mother-in-law and her husband Hiroyuki's affair. While talking,they become comfortable and familiar with each other.
The next morning, Asako wakes up and learns that Ririka has already prepared breakfast. Asako happens to overhear a conversation from Ririka. Asako feels she can't trust Ririka anymore. A missing person case occurs with one of their neighbors. Detectives then arrive at their home.