Kiyoshi, a brilliant detective, inquiries on mysterious cases with his childhood friend, Ishioka, a novelist.
Kang Qiao (Huang Zitao) witnesses Xia Yingying (Yang Caiyu) in the process of committing what could be a crime, but yet is drawn to the beautiful girl. After getting to know her better, Kang discovers that there are even more mysteries surrounding Xia and finds himself placed in serious danger.
Private Detective Kiyoshi Mitarai and Miyuki Ogawa arrive in Fukuyama, Hiroshima Prefecture. They are interested in a case which involves discovered bodies. The bodies were found drifting in the Seto Inland Sea, where the currents repeat every 6 hours.
