Eyaminokami - The Plague Princess

Sounji Nagare was in despair at his own incompetence and the contrasting, sheer brilliance of his younger brother. But his destiny takes an unexpected turn when he meets a beautiful young girl who calls herself "god." Where will his family’s secret dark occupation and Nagare's bloody past take him? An original story by GTO's Toru Fujisawa is given new life as a manga by Happy Project's Hirokazu Ochiai in this out-of-this-world fantasy.

(Source: Manga Box)