Shinigami x Doctor (シニガミ×ドクター) is a manga series by Kemuri Karakara. It was serialized in ITAN.
Living inside humans, and in the end, inducing the death of its host, the plant that can bloom into an enormous flower, also known as the "Shinigami's Flower", suddenly appeared in the world. It is a "God of Death" that doctors are unable to cure. The only people able to face such overwhelming power are the doctors of Gokurakuen, an medical Institution that travels around the seas. Ichinose Souma, a doctor of Class One in the Gokurakuen who is still unknown, receives a request, and pays a visit to the patients house.
- Karakara Kemuri Wiki - Wikia on the manga's author.