Huh! Yes they do! Um. Not all of them cause theres a lot of ocs but; Mira's full name is Mira Phronima, Sasha's is Sasha Steadyfin, Cynthia's is Cynthia Vermeil, and Ingrid well.. she doesnt have a last name.
Had to think of ones for my agents but; Yon Yuzuki, Hachi Ida (I think when making legal documents for her, Marina went like; uhhh she's my uhhhhhhh cousin and Hachi just gave a thumbs up), and San (and technically Neo) Akkar