This is a posable action figure from the Nendoroid series.
From the Good Smile Company website:
From the anime series "LoveLive!Sunshine!!" comes a Nendoroid of the Aqours member Dia Kurosawa wearing her outfit from the song 'Aozora Jumping Heart'! She comes with both an elegant smiling face plate as well as an upset, blushing face plate for when she gets annoyed with the other Aqours members! A folding fan is also included which can be held over her mouth to add a different feel to each of the expressions!!
A selection of different parts are also included which allow you to pose her in different dance poses from the opening theme of the anime series! Be sure to enjoy her together with the other members of Aqours!