Shinigami trilogy manga

Shinigami Trilogy summary:

Furoku is a Shinigami who fell in love with a girl, Himeka, while waiting 6 months for an old man to die in the hospital. The problem is, she is supposed to die in heart surgery, and not only that, she's meant to go to hell. The reason being, she was born with a weak body, but dreams of taking over the world if she had a stronger body. So, Furoku offers some of his life up to save this "girl who hasn't done anything wrong". What future lies ahead of Fukuro and this "Bloody Queen"?