lyrical school have announced that yumi has left the group.
According to the announcement, it seems her poor health has made it hard for her to continue with the group and lyrical school will continue only as ayaka, ami, mei, minan, and hime.
The rigorous medical treatment did not combine well with the energy and exercise that the group goes through during lives, so she took the decision to leave the group as a result.
A video from her announcing this can be seen at the link below.
While sad, the announcement seemed to be coming since she has been on hiatus for months now.
Her deciding to leave is understandable though, since health is important and while performing for fans is fun, her health is always more important.
We wish yumi the best as she recovers, get well soon!