Persona Q will be released June 5th on the Nintendo 3DS in Japan. The game has no Western release date just yet. The newest members of the cast are Zen and Rei, featured in the videos shown below that Atlus has recently added to their YouTube channel.
The youngest member of S.E.E.S, Ken Amada from Persona 3, joins the group along with Shiba Inu Koromaru as playable characters.
Source (http://www NULL.siliconera NULL.com/2014/01/30/persona-3s-ken-amada-koromaru-jump-persona-q-shadow-labyrinth/?utm_source=feedburner&utm_medium=twitter&utm_campaign=Feed%3A+siliconera%2FMkOc+%28Siliconera%29)