Monster no Niku wo Kutteitara Oui ni Tsuita Ken

Mars, the first prince of the kingdom of Farune, is twelve years old and lives in fear of assassination. Suspecting poison in the food served at the castle, he slips out into the monster-infested forest beyond its walls and hunts his own meals. One night he meets a greatsword-wielding woman who sees promise in him and offers to train him as her apprentice. She reveals a secret that few people know: eating monsters makes you stronger. As his power grows, Mars's struggle against assassins expands into wars and political plots that spread across the kingdom and the continent.