Now that I've seen your pleasing PM in the other site, I have sent back the information you'll need to manage those two characters in dialogue scenes with Hannah's and my characters. An added note here: since Toru and Wendy have known Melody for a fairly long time, it is logical that they would at least have heard of the existence of other friends of Melody's. Therefore, it should be easy to justify them introducing themselves to Melody's recently-turned-up friends Shadow and Alyvia. This would enable us to get those two players more integrated into the mainstream of the RP.
(If you contact Shadow2345 and Skitz about this, please let them know that I encouraged it.)