User blog comment:Hielmiez/The New Queen Idol Reveal! Hype for S2!/@comment-29742182-20170129031527/@comment-3487190-20170130171918

Presumably, most of the main rookie characters might all become S4 then create new brands one day, so the idea of "inheriting" is only a temporary matter. Letting non-S4 students wear new premium coords is the only possible way, I guess the plot would manage to make it happen.

As Mahiru has the best chance to become S4 and create own brand in the second year, the person that can introduce new RK coords is Koharu, despite she's still absent now.