The "Otherworld" is a vast and dangerous realm hidden from the knowledge of the common folk. It is also home to many creatures that threaten any human who dare visit it. To witness its desolate yet oddly absorbing environment, one must search for portals that could reside anywhere, from secret elevators to shrine entrances. After a fateful encounter with a horrendous Otherworld denizen, Sorao Kamikoshi ponders whether to keep going or give up in life. Meanwhile, Toriko Nishina scours the Otherworld in hopes of finding her friend Satsuki, who she believes is lost somewhere within the realm. When the two cross paths, friendship blossoms. In order to acquire as much information about this obscure dimension, the two travel back and forth from the real world to the other. Sorao and Toriko's bodies are soon influenced by the Otherworld, preparing them for the many horrors to come as both of them try to fulfill their goals.

Two siblings were happy on Mt. Olympus, until they fell in love. Deimo's sister Venus got imprisoned in the Swamp of Death. To save Venus's life, he must find a human reincarnation so that they can continue their love.

While walking home, Mikiya Kokutou comes across a familiar sight: Shiki Ryougi standing by a railing amidst the falling snow, just as when he first met her four years ago. While the two talk of their past and shared experiences, Mikiya realizes that something is strange about Shiki; rather, this is not the woman he has come to know, but an entirely different entity that dwells within Shiki's body...

Giovanni is a young boy who lives on the outskirts of a small rustic village. His mother is bedridden and his father has not returned home since leaving to work on a fishing boat. An outcast at school, Giovanni has only one friend: Campanella, the mayor's son. During the town's Festival of Stars, Giovanni starts to daydream atop a hill and looks up to find a steam engine train floating in the air. He boards the train only to find his friend Campanella already there. And so, the two begin their journey through the stars where they come across unusual people and visit many beautiful and haunting places.