Aka is an erotic visual novel developed by NekoNekoSoft. Desert lands in the ancient times. There was a legend about entity called Ruta who bestows various magic-like abilities upon his disciples along with vermillion gems. Story begins to unfold with the adventure of two people -- Aramis, young girl from the Ruta clan, who can erase people's memories, and Kadan, her guardian. There are four chapter in the novel, that are connected by the same setting.