She is Nishino Nanase (西野七瀬), a Nogizaka46 member who recently announced her graduation. She debuted in 2011 as the first generation of idol group Nogizaka46, the 1st rival group of AKB48. In her 7 years, she has done various type of works as an artist, singer, and actress.
Graduating means that she's leaving the idol group. There are members who graduate to be able to live a normal life, while the others are trying to pursue their solo career, like Nishino.
She has done lots of works as Nogizaka46 Member. Hopefully, in the future she will do more as an solo artist.