Ortwin

An archduke candidate from Drewanchel. He is the younger brother of Adolphine.

Despite being heavily pushed to become the next Aub Drewanchel, Ortwin himself would much rather leave the title to his half-siblings and dedicate his life to research. He finds it very difficult to disobey his sister and thus works diligently on achieving the excellence expected of the next archduke.

(Source: Ascendance of a Bookworm Wiki)