A third grade elementary school girl whose mother, Miori (originally from Shioshishio), died when she was young. She met Akari a couple of times and played with her when Akari came to visit Miuna's mom and the family. Sayu's best friend. She has a crush on Hikari.Even after the timeskip, she still loves Hikari. She also develops Ena later on allowing her to breathe underwater. (Source: Wikipedia)