沢井 夏葉
from Monobeno: Sonogo no Natsuha no Nanatsu no Natsu
Tooru's younger sister. In Alice's and her own routes, she contracts the disease called "IAGS" which causes her body to age rapidly. In Sumi's route, she is afflicted with a curse called "Tokigami" which steals away her time, thus also causing her to age rapidly.
Monobeno: Sonogo no Natsuha no Nanatsu no Natsu