Ore wa Mada, Honki wo Dashite Inai

The main character, the fourth son of a noble family, is forced to take over the household after his three older brothers die in a meteorite incident. They were all members of the same political party, leading to his unexpected inheritance of the title. His remaining older sister renounces her family ties and officially becomes his foster daughter, addressing him as "dad" in an effort to push him into proving his capabilities as the new head of the household. The story includes a prologue and six additional bonus chapters.