俺の妹は悪女だったらしい

Nia, the eldest son of a counts family, was executed along with his entire family by the First Prince, Philbert, because his younger sister harmed the Saint... or so it should have been, but when he opened his eyes, he had returned to seven years ago when he was 16. To save his family, Nia resolves to strictly train the sister he used to spoil and vows to become stronger himself. However, by preventing the fateful meeting between his sister and Philbert—the very root of their destruction—Nia somehow ends up catching Philberts fancy and becomes his close aide...?! The long-awaited manga adaptation of Ichijinsha Melissas immensely popular BL novel!