Rumia is not suppose to appear in this game actually but to progress one NPC's questline you need to go to hiding lair of Succubus and incubuses. Since Ryoko can't enter that spot Rumia being a former one I thought it's best she comes to players rescue. There were actually 48 characters that suppose to have multiple animations and Juko was one of them but I've reduced number of characters that will appear in this game.
People are gonna like almost all of the questline except the main major questline. The secondary one will be more favorable with what it offers as reward.
Yeah, those SCP-610 instance are also in other game of mine. If you read their data on SCM Database website inside the game you will have an idea what I'm planning with them.