Sumire Souma

She is classmate of Misora and Kei in their middle school and also Kei's class representative.

She dies slipping and falling into the river from a bridge on the mountain she had gone to for hiking.

Souma is a successor of Majo's ability. She has the same powers as Majo which is to see the future. Thus implying the possibility that she wanted to avoid leading the same isolated life like Majo had which might have led her to suicide.