As Aizawa and company arrives at the accident site which is the central station concourse, several adults are in commotion. To commemorate the opening, a field trip event was held and there were around 300 participants. Shiraishi in charge of commanding the medical team, made Aizawa and Fujikawa go towards the collapsed 2nd basement. Saejima, without thinking, told Fujikawa "Don't go." However, Fujikawa left Saejima and went down to the basement.

Crossing more than 10 years in their career, they start to face that era where they reach various roads to walk on, their work, and their private lives. Aizawa Kousaku left the lifesaving center of Shoyo University Hokubu Hospital, devoting himself as a brain surgeon aiming high to perform operations every day. Shiraishi Megumi, due to the insufficient aide in the Shohoku lifesaving center now is struggling as the leader of the flight doctor staff. Once with them in aiming to be a flight doctor, Hiyama Mihoko left Shohoku Hospital and is now an obstetrician and gynecologist in a perinatal care center. Saejima Haruka even now continues to be an ace flight nurse. And Fujikawa Kazuo, together with Shiraishi supports Shohoku lifesaving, has become a lifesaving doctor with specialization on orthopedic surgery.

With Amano Kanade's emergency operation and supporting another patient's sudden change in condition althrough the night, Aizawa Kousaku is unusually completely exhausted at their medical office. There, Fujikawa Kazuo carries in his arms a box of tomatoes as he reports for work. It's the tomato that the pregnant Saejima Haruka can only eat. Fujikawa complains that Saejima does not accept other food and if there's no tomato she gets in a bad mood but he looks happy in saying so. Hiyama Mihoko consults Shiraishi Megumi on the case of a guy you worry about having a wife but hides it under a story of a friend. However, with Shiraishi answering in a loud voice don't go into adultery, the other party Hiyama's consulting was mistakened and regrets it.

Because of Aizawa Kousaku and Shinkai Hiroki (Ando Masanobu), Amano Kanade's surgery safely ended. However, when Shiraishi Megumi asks Shinkai about it, the enunciation was quite bad. Kanade's parents seem to understand the result of the surgery however... On the other hand, a 17 year old high school male student has been given a diagnosis of brain death. That implies to Tachibana Keisuke that the potential heart transplant for his son Yuusuke has probably come. With cardiovascular doctor Inoue Nobuaki's identification, Tachibana reins himself not to hold expectations.

Aizawa Kousaku visits the office of department head Saijou Akira (Sugimoto Tetta) and conveys his withdrawal as candidate for the Toronto University residency. Asked by Saijou if the cause is Amano Kanade's postoperative progress, Aizawa goes out of the room with no particular reason. Shinkai Hiroki then arrives and gets surprised hearing from Saijou about Aizawa's withdrawal.

Aizawa Kousaku tried to distance himself from the affairs of Amano Kanade's rehabilitation but even if he turns the other way, he rather hears Kanade's voice. That day is also the first day Haitani Shunpei resumes to work in lifesaving after being injured from falling of a train platform. Haitani's explanation of the fall from the platform was due to the effect of the sleeping medication but Shirashi Megumi and company suspects if it was suicide. Haitani perceiving such atmosphere, goes on normally but Shirashi and Fujikawa Kazuo too has become awkward.

Three people with emergency cases are brought in the 1st ER. One person is Morozumi Kohei, a 33 year old wheelchair rugby player. While warming-up during half time, wheelchair seems to have fallen down from stairs. Furthermore, there's a burn patient, and a patient who fell from a high altitude, all the 3 of them were brought in. Aizawa Kousaku gathers everyone's strength and with swift correspondense, the result is, 3 people's lives weren't lost and have been moved to the ICU. As Tachibana Keisuke thinks back upon months ago, he talks how Shiraishi Megumi has come to lead a good team. In the medical office, Natori Souma's father, Shouma was waiting. What is his father's purpose?

One week has passed since Aizawa Kousakuhas returned to the Emerg ency Lifesaving Center. However, his guiding principles towards the interns clash with Shiraishi Megumi that Hiyama Mihoko and Fujikawa Kazuo are at the point of getting fed up. Shiraishi is having difficulty in acknowledging Aizawa's strict supervision of Yokomine Akari and wants the center to return to its smoothness. She quickly starts to regret wishing Aizawa's return.

"Life and the thing that person thinks is more important than life. Which of it when the time comes that you have to choose, what will you do?" Aizawa Kousaku faces this problem.

Aizawa Kousaku receives information from Shinkai Hiroki that due to convulsion attacks, Amano Kanade has been admitted. Shinkai conveyed this when Kanade was talking to Aizawa. Even with Kanade being in this condition, she still doesn't want to accept surgery. Shinkai expects Aizawa's persuation. However, no matter how Aizawa calls out to Kanade, it's still uncertain.

Due to several reasons the four trainees will be alone during the night without a senior. A drunken man arrives that needs to have a complicated operation, that Aizawa and Hiyama perform with the help of the other two until a senior finally arrives. At the end of the episode, Shiaishi is allowed on the Heli, replacing Aizawa, who is not sohappy about this turn of events.

A gas pipe explodes in a factory causing over thirty casualties, one of which gets blown against a protruding iron bar. The senior doctors are busy, and the rescue can't help either. Dr. Mitsui's past is catching up with her, causing a stir in the hospital.

The four newbies will be doing "normal" work at the ICU, but they have the aim to right the Doctor Heli. However, only their supervisor decides who will ride on it and he'll base his decision on their skills. While Shiraishi fails to make the right decision on the actual scene, Aizawa can handle the situation. Meanwhile, Hiyama and Fujikawa have to realize that the "normal" work in the hospital is tough and emotionally challenging as well.

Aizawa's put in charge of a very important task; Fujikawa makes a mistake in the ER; no one seems to be able to identify Shiraishi's patient's odd illness; Dr. Kuroda is unsatisfied with Fujikawa's work, but is having a change of heart regarding Hiyama. Personal histories of the trainees start to unravel.

Aizawa makes a mistake when he chose a seemingly more interesting case and sent an old woman back home instead that later collapses and falls into coma, leaving Aizawa with feelings of guilt. Hiyama is allowed to get on the Heli, but at the actual scene she cannot do much. Since the seniors are busy, Aizawa comes to help her out. Meanwhile, Fujikawa has to deal with a man that is wearing bras and Shiaishi dealing with a woman with a broken nose that don't want it to be operated.

Aizawa's grandmother is hospitalized and suffers from demence causing her to not recognize her own grandson. Aizawa tried hard to not get emotionally involved to carry on his work properly, but in the end, he breaks down, crying while he takes care for her. Fujikawa gets a patient whose son had cast a curse on him. When all symptomps are alike the spell, he is on the verge of giving up, but Saejima, the nurse, finds out the cause.

Aizawa's grandmother refuses to eat, so Fujikawa tries his best, but can't bring her to eat. He asks Aizawa to come and spend some time with her, but he rather wants to operate and practise his skills. In the end, however, he visits her, although she still doesn't recognize him. Saejime gets visited by her ex-boyfriend, who is ill and sits in a wheelchair. She breaks up with him as he is a burden to her, though she feels really bad for being that egoistic.

A whole family keeps the four trainees busy. The mother and daughter are dominant, the grandfather doesn't care about rules (he leaves to take a look at the heli) and the father is calm. The lil girl is all over Aizawa, who grows fond of her too. The two male family members have to undergo an operation leaving their women worrying, but things go well. Shiaishi and Kuroda take the heli, but the scene is still dangerous and Kuroda saves Shiaishi from getting hit by a metal bar which lands on him.

Aizawa had to amputate Kuroda's arm at the scene and they were re-attaching it again, but with not much hope that he'll be able to use it again. At the same time, Kuroda's son has an accident and was brought to the hospital the heli wehere he had to undergo an operation. While doing so, they saw that the boy has a brain tumor. Shiraishi is struggling with the guilt she feels while Aizawa is worrying if amputation was the right decision.

Shiaishi hands in her resignation, but the boss doesn't accept it. When she goes to Kuroda to excuse, a patient's constitution gets worse and she has to perform an emergency operation with Kuroda supervising her. Hiyama, Aizawa and Mitsui get a pregnant woman and although it's dangerous decide to rescue the mother and the child. The ep ends with Hiyama, Aizawa and Shiaishi arriving at a scene of a mass accident with lots of injured.

In the final episode of the season, the four trainees have to fight to keep the victims of the accident. They manage to save several lives, but also loose some. Fujikawa is allowed to use the heli for the first time. They all show that they are able to give their best in complicated situations and were acknowledged by their seniors.

The four trainees are back, with a new supervisor who was hired to judge if they pass or if they still need training. This time, Aizawa rescues a child that was lying in the water for more than half an hour. He managed to reanimate him, but they don't know how much damage his brain suffered. Hiyama seems to start having problems with her heart and Saejima lives in her bitter-sweet relationship with her not curable boyfriend.

Hiyama is still suffering from her heart operation and wonders if she should let her heart be tested. Shiaishi tries to fly with the heli more that the other ones, never forgetting what Dr. Kuroda told her. Fujikawa has to realize that he also cannot save everyone when he loses someone on the scene after trying his best. What beats him the most is that if Aizawa had been on the heli, he might have been able to rescue the man. However, Aizawa tells him, that he also lost people this week.

A huge accident happened at a train station. Shiaishi is in charge for the tagging while all the other senior doctors and Aizawa are needed for 3 people that crashed on the stairs, a ski sticking through the body of the two people on top. There is only the possibility to save two out of three. Hiyama decides for an operation on her heart. At the end of the episode, Aizawa's father seems to be alive.

Hiyama discovers that Shiaishi had done a mistake in the previous night duty that was life threatening for a patient. She is told by her boss to take a break once in a while and Hiyama tells her that she shouldn't take all the work on her, but that they can do it together. A bit later, they perform a surgery together as none of the seniors is available which strengthens their bond. Aizawa has to deal with a young girl who's pregnant but doesn't want to have the baby.