In Anticipation of Tomorrow - S1.E6

After receiving checkups at the hospital following their battle against the Vertex, Fu is revealed to have lost some vision in her left eye while Itsuki has lost her voice, both of which they assume to be temporary symptoms caused by battle fatigue. However, upon discovering Yuna has also lost her sense of taste and that she herself has gone deaf in her left ear, Mimori fears that these symptoms could be a side-effect of the Mankai form and gets in touch with Fu about it. Meanwhile, Karin, who hasn't been affected since she didn't use the Mankai form, has been avoiding going to the clubroom, as she fears she no longer has any purpose now that the Vertex are gone. However, Yuna manages to find her and convince her that, even with no-one to fight, the Hero Club will still carry on like it always has. Touched by Yuna's friendship, Karin convinces Taisha to let her stay at Sanshu Middle School until graduation, while the girls make plans for summer break.