Gan Shometsu no Wana: Kanzen Kankai no Nazo

Natsume Noriaki is a doctor who works in a hospital that provides the best cancer treatment. One day, he is visited by a patient who suffers from terminal cancer. However, immediately after the patient has received the living benefits of his life insurance, his cancer goes into remission. The same thing then happened to a different patient. Noriaki starts to investigate this mystery with the help of Hashima Yuma, a strange research doctor who was his high school friend, and Morikawa Yuichi, an employee at a life insurance company. (Source: MyDramaList)