In a world where memories exist in memory chips separate from the body, death of the body no longer means death of the soul. It is possible for memories to be viewed, altered, and transferred between bodies. These memory chips are used by the rich to obtain eternal lives in carefully selected bodies, while for the poor, selling their own bodies and conserving their souls in the chips often become the only way to earn a living. An electrolytic cloud in the sky serves as a barrier between the heavens of the fortunate and the underworld of the destitute, making this social division impregnable. One day, a man named Kaiba wakes up in an empty room with no memories, a mysterious hole in his chest, and a locket holding the picture of an unknown woman. After escaping an attack and stumbling upon a decrepit village of underworld residents, he begins his adventure across the different planets of this strange universe to find out more about his own identity and the woman he once knew. Through a journey of self-discovery and acceptance, Kaiba weaves together tales of souls and spirits and explores the importance of memories. [Written by MAL Rewrite]

A two-episode special. They are designated as Episodes 13 and 14, and the first episode is a direct sequel to the previous series while the second episode is about the trans-sex of Natsuru.

Ryouhei Arisu is a high school student with no ambitions and just wants to escape from what he feels is a meaningless reality. One night when he is with his two friends Daikichi Karube and Chouta Segawa, they see an abnormally large firework shoot into the sky, an event which signals a permanent change in their lives. Blinded by the incredibly bright explosion, the three find themselves transported to what is known as the Borderland. The only inhabitants of this world are participants of a deadly game where specific tasks must be accomplished if they wish to survive. As the three begin playing to determine how they can get back home, Ryouhei finds himself feeling alive for the very first time in his life. [Written by MAL Rewrite]

OVA bundled with Niθ Art Works Vol. 2, featuring a new character named Kagekatsu Uesugi.