Shinigami Trilogy

A Shinigami named Furoku develops feelings for a girl named Himeka while observing an elderly man's final six months. Himeka is destined to die during heart surgery and is fated for hell due to her weak body and ambitions of world domination. To save her, Furoku sacrifices part of his life. The uncertain future of Furoku and Himeka, referred to as the "Bloody Queen," remains to be seen.