Exstetra is a role-playing game that is being developed by FuRyu, for the Nintendo 3DS and PlayStation Vita. It is set to be released on October 17, 2013 in Japan, with no word on a localization outside of there. The game focuses on Ryoma Narusawa's ability to absorb "Ex" from enemies and transfer this power into other people by kissing them, making them Knights of Prisma.
One day, Tokyo is fused with another world and becomes a different place. This world, called Amazia, is destined to be destroyed. Ryoma Narusawa, the main protagonist, is being called the Prisma, a being who is destined to save the world from destruction. It is up to Ryoma to save the world and return Tokyo to its former self.