Responses
You forgot the part where they mentioned that a valedictorian never loses their title even after death and that it is inherited instead. Kurokiri more than likely inherited her title.
Kurokiri's ancestor was the forst eprson in the school's history since its creation to receive the valedictorian title. So Kurokiri just inherited it like a royal title.
Let me get this straight, so the valedictorian of each year gets to be inaugurated in the Guardians’ Society. As the first valedictorian, wouldn’t that mean Yu Kurokiri is over a hundred years old? She looks so young if so