Monoe (モノ江), (derived from monochrome) lives in the White Desert and most players consider her to be Monoko's older sister. Her name comes from the "Picture/モノ江.xyz" file in the game, and is thus one of the three characters with an official name, other than Madotsuki and Monoko.
She is located in a tunnel near Dave Spector. To meet her, you must kill Dave Spector with the knife and walk into the tunnel from the west. She will be somewhere in the darkness - it is a good idea to use the Cat Effect to locate her.
Interacting with her will trigger a brief full-screen event, where a picture of her face will fade in and out upon the screen. After this, she vanishes away to another place in the area.In YUMENIKKI -DREAM DIARY-, she is seen in a school crying. You have to collect four scraps of a photograph, assemble it and show it to her. She is next seen in the Staircase, sitting on the stairs next to KyuuKyuu. Approaching her will cause her to scream at you and a jumpscare-y full-screen event takes place.
Monoe could be a vision of when Madotsuki was happy (or how she wants to be happy). She is one of the only characters that smiles and doesn't seem hostile (like Uboa) but then she disappears. Monoe and Madotsuki also share similar appearances (shown by the picture above).