do you mean mao?My thoughts exactly. The girl could pass for Flonne. Maybe she decided to don more of a Fallen Angel look. And the guy on the far left looks like Valvatorez from behind w/o his cape.
flonne has blue eyes and blond hair. this girl has pink hair and red eyes. i thought it was artina, but she has pink hair and blue eyes - but she is the closest in resemblance.
i think it's a stretch for any four of those people to be returning characters, but i wouldn't put it past them to pull a disgaea all-stars with this. i mean, axel and raspberyl from d2 and d3 respectively were major players in d4.