is a Japanese manga series written and illustrated by Naoki Urasawa. It was published by Shogakukan in their Big Comic Original magazine between 1994 and 2001, with the chapters collected and reprinted into 18 tankobon volumes. The story revolves around Kenzo Tenma, a Japanese surgeon living in Germany whose life enters turmoil after getting himself involved with Johan Liebert, one of his former patients who is revealed to be a dangerous psychopath.