Непутёвый ученик в школе магии: Наследование Йоцубы

Movie adaptation of Mahouka Koukou no Rettousei's Yotsuba Succession Arc.

The invitation has arrived. It is time for the New Year’s Reception at the Yotsuba family residence. This year, Miyuki and other candidates will gather there to decide who will be the next leader of their powerful clan. If chosen as the successor, she would never have to see her brother live as a pariah ever again. At the same time, such a position surely entails a political marriage, plunging her mind into complete turmoil. Complicating matters, the current head of their family sows doubt with the shocking claim that Miyuki is not Tatsuya’s sister. When the new year comes, their relationship may be changed forever...

(Source: Yen Press)