is a calm girl who is very diligent. Due to having weak health, she is always seen with a parasol when outside. She enjoys reading, especially when the story contains boys love elements, and her room is filled with books. She carries around a book of poems by Bokusui Wakayama. In the real world, she was feeling guilty over having forgotten an imaginary friend she used to have, who comes to life in the artificial world as Midori. She uses the parasol because she is trying to hide that she has no shadow; this is due to Midori using Mio
's shadow to materialize her own body. Mio was originally designed by Na-Ga to wear glasses, but this was later dropped. However, players can still view her CG with glasses during Riki's déjà vu flashback of Mio
, though this is meant to be a deception by Midori.