In Japanese society, it is a very common practice for patients to give doctors gift money.
Of course, minor ailments do not entail such practice, but for more serious illnesses such as surgeries or diseases requiring hospitalization, patients usually prepare a gift for the attending physician prior to the surgery or at the time of discharge as a token of gratitude.
This is why the medical profession in Japan is so popular, because if one becomes an attending physician, their unofficial income often significantly exceeds their salary.
As for the income of a doctor, it is already quite high. Taking someone like Nakagawa Susumu, a Trainee Doctor, as an example, his annual income is around seven million yen, with monthly earnings about 400-500 thousand yen. In Japan, this level of income is considered very good, allowing for a comfortable life even in a large city like Tokyo.
