Image from: Tokyo Girls Update
On December 11, Takeda Saki and Nakano Yumi announced they would be graduating from the group.
According to comments from the members, Takeda Saki will graduate to continue her studies abroad. Nakano Yumi will be leaving due to a leg injury that has worsened as the tour has proceeded and instead will work hard to become a solo singer.
It seems quite sudden, but the reasons for graduation are valid. After all, Saki is 20 now and idols are well known for leaving groups fairly early to accomplish other goals they might have. Yumi on the other hand, has a more pressing issue with her leg injury and performing idol songs do take a toll on their bodies.
Hopefully fans can continue to give them support until their final performance set for December 28.
Source: Tokyo Girls Update