A girl who went missing after an accident returns 10 years later and reunites with her grandmother.

At the same time as murder suspect Yeo-hoon is brought unconscious to the emergency room following a shooting incident, an assailant breaks into the house of Tae-jun, the emergency room's doctor in charge, and kidnaps his wife. The kidnapper calls the doctor and tells him to bring Yeo-hoon to him. To retrieve his wife, Tae-jun has no option but to save the patient and sneak him away before the police can notice.

Following the story of Ran, who confronts a mysterious organization by participating in a no-rules deathmatch after discovering her missing younger sister Yuzuki is involved in a crime. With danger at every corner, Ran must trade in her boxing gloves for brass knuckles. Will she save her sister?

In 2025, a scientist on the verge of making a major discovery related to time travel is suddenly put in peril when a rival kidnaps her young son and demands a hefty ransom: her entire research.