Shinigami Trilogy

Fukuro is a Shinigami who falls in love with a girl named Himeka during the six months he spends waiting for an elderly patient to pass away in a hospital. However, her fate is sealed: she is destined to die during heart surgery, and worse still, her soul is bound for hell. The reason lies in her contradiction—though born with a frail body, she harbors dreams of world conquest should she ever possess a stronger one. Moved by a desire to save a girl he deems innocent of any true wrongdoing, Fukuro offers a portion of his own lifespan to alter her course. What future awaits Fukuro and this would‑be "Bloody Queen"?