Lucifer no Migite

A doctor named Yu went to Africa for a volunteer project but was captured by a guerilla group during a civil war and forced to treat their injured for years. After the group was targeted by the new regime, Yu was placed in a life-or-death situation and abandoned medicine, getting a Lucifer tattoo on his right arm as a reminder of his past. Returning to Japan, he falls into a life of drinking. One morning, he wakes up in a clinic run by Dr. Minatono, who treats all patients regardless of their ability to pay and uses advanced equipment. The clinic serves clients like the mob who cannot access regular hospitals due to legal issues, and in return, it receives large payments. Yu initially refuses to work there but ends up frequently involved in surgical cases.