Mio Nishizono
Mio is a calm and shy 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. Mio was originally designed by Na-Ga to wear glasses, but this was later dropped.
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.
In Mio’s Bad End, just like everyone else, Riki forgets that Mio ever existed and sees Midori, Mio’s imaginary friend as the real Mio.