Nepgeo (ネプギマ,Nepugima?) is a minor NPC that lives in Planeptune. She looks like Nepgear, but is very crude. She will tease and insult the player if they attempt to chirper with her. She also has an ASIC colored clip in her hair.
One possibility is that she's Linda in disguise. However, Nepgeo is still present in Chirper in the Conquest Route after Linda is killed.
Her original name is a reference to the Neo Geo, an arcade system and home console released during the same generation as the Genesis. They both had a large library of arcade ports. Neo Geo also released a portable version known as the Neo Geo X in 2012 which shares some minor level of visual similarity to the Sega Game Gear.