Tokyo MER was launched to save the lives of patients by rushing to the scene of accidents, disasters, and incidents. There are 7 members of the emergency team: Chief Doctor Kitami, Resident Tsurumaki Hina, Nurse Kuramae Natsume, Vietnamese Nurse Hoang Lan Minh, Anesthesiologist Fuyuki Jiro, civil engineer Tokumaru Motoichi, and the bureaucrat and doctor Otowa Nao. All of them are life-saving medical specialists. During the inauguration ceremony, the team have to rush to the of a serious bus accident. There were many patients waiting and the team takes on the mission of operating on multiple patients at the scene of an extremely dangerous accident. Kitami's life-saving act, transcending the common sense of doctors, is regarded as a problem by the Ministry of Health, Labor and Welfare. Tokyo MER, which faces the crisis of dissolution soon after inauguration is faced with a difficult decision when a factory explosion occurs.

Tokyo MER is dispatched to a construction site where a steel frame has fallen. Hina opposes Chief Kitami who puts himself in danger operating on-site. A mistake by Hina puts a patient at risk resulting in her confidence falling. Ordered to dispatch to an explosion accident at the Summer festival, Hina is faced with a large number of critical patients and the heavy responsibility of protecting their lives as a doctor. Can Hina, entrusted with a serious operation by Kitami, overcome the trial of life?

An incident occurs in which a thug holds a seriously ill girl hostage. A bullet flies into the downtown area. Tokyo MER's Kitami Kota rushes to the scene, claiming that without medicine, the girl's life is at stake. He confronts the police who only care about honor. To save the life of a girl whose seizures put her life at stake, Nurse Kuramae Natsume volunteers to replace her. Natsume, a single mother with a daughter, has a strong desire to save the girl. However, in the meantime, the criminal shoots at Natsume...

A tunnel collapse accident has occurred! Kota Kitami rushes to the scene and finds out that the doctor carrying a heart meant for a transplant is buried in the rubble. He tries to rescue him, but another collapse occurs. Still, Kitami tries to rush alongside Senju Mikio and Kuramae Natsume. On the other hand, the female patient awaiting operation by Takanawa Chiaki is approaching the time limit of her life. All member use their courage to challenge the "relay of life"!

The elevator carrying Kitami Kota's younger sister Suzuka and a pregnant woman suddenly stopped due to a fire! She is trapped alongside Otowa Nao and politician Amanuma. The condition of the pregnant woman suddenly changes as the elevator fills with smoke and oxygen levels go down. The dispatched Tokyo MER is ordered to prioritize the rescue of the politician. The ultimate choice for Otowa as the elevator close to flames. What is Kitami's decision to save the life of mother and child? Members of MER challenge the rescue drama of death!

A mysterious incident occurred in which 18 elementary school students suddenly disappeared in the mountains. Kitami of MER heads to the scene and decides to disperse the members in order to search for and treat the children. The members who have overcome the pinches as a team so far fight apart from eachother. While Otowa Nao and Tsurumaki Hina are struggling to treat the children who has an unexplained serious illness, Kitami desperately treats them but the medicine he has is not enough. The biggest crisis strikes Kitami.

Tokyo MER is dispatched to an area where foreign workers are complaining of unexplained symptoms. It seemed to be a mass food poisoning incident but, for some reason, the scene is occupied by police officers. Kitami tries to transport the injured and the sick over finding out the truth of the incident but Public Security detective Tsukishima appears and detains a patient. Behind this incident is a big government shaking event and Kitami's secret... his blank year...

At a certain hospital, all medical equipment stops due to a power outage! Panic occurs as many patients face death. Kitami and the other MER members are dispatched but Otowa, who now knows the truth of the blank year, rebels. He refuses to obey Kitami's orders and the relationship of trust between MER member's collapses. Meanwhile, a terrifying crisis strikes Kitami who has headed off alone to restore the outdoor generator to save patients.

A carbon dioxing poisoning incident occurs at a foreign embassy. The MER team is dispatched but are unable to enter without permission due to legalities. On the other hand, Governor Akatsuka collapses due to a chronic illness. Kitami and rescue commander Senju head to the rescue in an underground parking lot and get locked up. As time goes by, oxygen diminishes and the patients condition deteriorates. In desperation, they take a dangerous bet to save lives.

Kitami is suspected of being involved in a terrorist organization and was ordered to ban dispatch. Meanwhile, there was a bombing incident at a university. Kitami and Otowa rush to the rescue but it was the trap set by Tsubaki Elliot who set up a further bombing. The two are injured in the school building where the bomb was set up. However, the students believe in the rumors on SNS that suspect Kitami of being a terrorist and behave ridiculously. The biggest crisis has hit them and finally, the first death will occur...

Kota, who lost his beloved sister, announces his withdrawal from MER. The governor, Akatsuka, wallows in a comatose state. Otowa decides to dissolve MER. Meanwhile, a series of terrorist bombings done by Tsubaki Elliot burn all over Tokyo. Many are injured, but no one calls to dispatch MER and the ER car is prohibited. The members are in a pinch but, at that time... The story of the last dispatch of MER.