From MangaHelpers:

Riding in on an ambulance on her first day, Hanashima Ruka is a new doctor-in-training with the emergency services of Kamakura Hospital in Kanagawa Prefecture. She's worked hard to become an emergency doctor, a dream she's had ever since her own rescue after an explosion in the subway. She never was able to learn the name of the doctor who carried her out of the rubble, but she's determined to be just like him. She knows that being a doctor in the ER will not always involve the thrilling experience of saving lives-- the ER patients have the worst and most urgent problems, and even with the best of care, many of them will die. In the company of her fellow trainees, and under the guidance of the relatively young male supervisor, Dr. Sanno, she is determined to give her patients the best care she possibly can! [tethysdust]