Only 5 are for sure cemented in place: Cinead in the top left, Orion in the middle, tsugi to his right, Pamela to Orion's left and Gwen seated next to her. That leaves two back rows and most of the front row to maneuver with
Furthermore, nera, Isolde, Andrew, and Arielle form most of the backmost row. Only one seat is left back there, but which seat depends on who's in a far corner: is nera in the bottom left, or is Andrew in the bottom right of the square.
Edit:
-Marcel cannot be sitting directly in front of Gwen, Pamela, Orion, or tsugi because Braeyden is behind him. By extension, fuyoko cannot be seated in front of all those options except tsugi, on account of her being next to him. This also means Marcel cannot be behind any of them either because that prankster would be in the way of nera, Isolde, Arielle, and Andrew.
however, if Andrew is in the far bottom right corner, then Braeden could sit all the way in the back left corner and Marcel could sit behind Gwen with fuyoko to his right. This also allows Melanie to sit by fuyoko, In front of Isolde.
this would all be flipped in the opposite direction if nera was in the back left corner.
But then Gina has to get in the way because she's right next to Braeden. damn it, guess I'll keep working.
Everybody else is in chunks together, and I'm not sure it'll all fit the way it's currently configured. but it's worth a try!